It's easier than it looks.
Really. I've made it twice! I should know. Actually, I've made it three times but I really didn't like the uber-scrappy version I tried to make... it didn't work for me at all. There was just way way too much going on... though, come to think of it, that's how my life was at the time so I'm sure there was some kind of cosmic connection.

After Sinta picked Hook for the March Schnibble, it occurred to me that I really ought to pass along some of the tips I shared with my class at Olde World last month. Sadly, some twit didn't think to save the demo pieces I made for class... Rosie's never been very good at anticipating that sort of thing.
Here's the first thing you need to know... it's a Schnibble thing. For most of the quilts I've done as Schnibbles, the first, last and most important thing to keep in mind is that there could very well be an easier way to cut out the quilt. But not if you're starting with charm squares that measure 5" x 5". From the very first quilt, what interested and challenged me with these quilts came down to a single question - what could I make using no more than 84 charm squares and a little bit of additional yardage? Some of the quilts have a very efficient use of fabric while others... well, not so much. Factor in that I like to trim pieces to size - something I know I have in common with many quilters - and there are some decisions I make that often require more explanation than I have room for in the pattern.
With Hook, the six 60-degree triangles used to make the block are pieced. There are two ways to do that - cut the pieces individually, assemble the triangles and hope that they're pretty accurate and bear some resemblance to a good 60-degree triangle. It works... but if there's a way to piece first and trim after, that's the way I prefer to do it.
On a side note, there are those "in the industry" who regard such methods as a "crutch". We should all be able to piece the units perfectly. Every. Single. Time.
Whatever.
Just as I wouldn't deny someone with a broken leg the use of a crutch, I think it's silly to chastise someone for using a tool or technique that lets them get those results a little more easily. So there. ;)
That explains the odd sort of strip set you're going to piece.

The reason the background pieces are a different size than the print pieces is two-fold - it gives you a skosh more room to trim and the print pieces were as big as I could cut them using charm squares.
There are three things to keep in mind with piecing these strip sets. First, one strip set will yield six (6) triangles, enough for one block. For the quilts I made, I used three triangles each of two different prints. Second, if you're using a single background for all the blocks, you don't have to piece the strip sets using three matching print pieces. As long as you use three rectangles of each print, you'll wind up with the necessary number of triangles.
Third, seam allowance is important. Technically, it isn't because you won't be relying on it for a measurement. But if your seam allowance gets too big, you'll have less room to trim and you'll start having issues with seams in the lower right corner. So keep your seam allowance to a scant 1/4" and you're good to go.
Oh and yes, press the seams open. Open. Open. Open.
After you piece the rectangle, I recommend that you clean up the top and bottom edges. They just need a little "shave" to make sure they're perfectly straight and even - if you trim too much - even an 1/8" - will put a little more seam in the corners of the triangle.

When that's done, you're ready to start cutting out the triangles.
Rulers or templates. A 60-degree triangle ruler is recommended because it's easier. I have and like the Creative Grid ruler but any 60-degree triangle ruler will work. The Marti Michel ruler comes in two sizes, either one will work. There are also other brands so as long as the ruler says 60-degree Triangle, it should work. If the ruler doesn't have a line for 3 1/4", use a piece of tape to mark one halfway between 3" and 3 1/2".
Correction: The Tri part of the Tri-Recs ruler will not work, the angle isn't 60-degrees.

By the way, a few weeks ago, when I was working on something else, I wanted to mark some lines on my ruler. I couldn't find the Glo-Line tape - 3 colors and I couldn't find any of them! - but I did come across a roll of pretty washi tape so I decided to use that instead. I loved it! It's pretty. It's relatively transparent. It works! (If you're not familiar with Washi Tape, it's a decorative paper tape that is easily found at scrapbook and hobby stores. It's relatively inexpensive... unless you become obsessed with all the colors, patterns and designs.)
You must - MUST - start with the background rectangle on the left side. If you don't, you're going to need more rectangles because the position of background and print will be wrong. It's as simple as that.

Like this.
Using a rotary cutter, trim the triangle as shown. While you can cut a little past the tip of the ruler, don't trim too far past it.
As you trim, your triangle will include a tiny bit of the seam in the bottom right corner of the triangle. Don't worry, I'll address that in a moment.

I found it easier to trim the three triangles on the bottom first before turning the strip set around. And no, don't trim the sides off yet - see the next picture.

You'll trim two more triangles from the remaining side for a total of 5 triangles. All five (5) triangles will match when it comes to the position of the background and print halves of the triangle.

You'll be left with this.

Trim the two side triangles as shown. You'll have to piece them to get your sixth triangle. Scant 1/4" seam allowance... press the seam open... trim the bottom edge straight.

Then FOCUS and trim the sixth triangle. (I'm sorry about the blur... I move fast.)

Any corners that have a seam in them, I just trimmed them right on the stitching line to remove the seam and the extra layer of fabric. So long as its just a tiny little nick like this, you're good to go because it's well within the seam allowance.

And there are your six triangles - matching or not.
I'm sorry for not making a second strip set so that I could do alternating triangles but the upside is that this is another option. I rather like the spinners this way too.
A couple of things to keep in mind as you are assembling the "block" from here:
- Every seam joining two triangles will have one piece with a long print edge and one piece with the seam in the center. If you're matching seams or there are two plain edges... stop!
- The triangles should match each other perfectly making it easy to match them up. (I love that part.)
- The scant 1/4" seam allowance should start and stop in any "v" that is there, or on the corner of the flat tip. It will make sense when you see it.

This is the easy part - piece two pairs of triangles exactly the same way. Piece only two pairs. Whether you're using one print as shown or two, piece them the same way. Trust me on this - been there, done this. Scant 1/4" seam allowance - press the seams open.
Then add the two remaining triangles - matching or different - to the sides to finish the block as shown.
If you're using two different prints... If the three triangles in the top half are aligned Red - Green - Red, the triangles in the bottom half need to be Green - Red - Green. I promise.

Lining the triangles up at this point is still easily done. It's because you trimmed the triangles after they were pieced... they're perfect. (Crutch... schmutch.) (And yes, I've been known to utter the words "I told you so" once or twice in my life.)
Scant 1/4" seam allowance - press the seam open.

That little triangle on the right... trim it off. But don't trim off any other little points - not yet.

Two halves.
I chose to piece the quilt top using vertical half-rows. The blocks aren't completed until I join the two adjacent rows together because it made the setting pieces on the alternating rows easier to assemble. But, yes, the blocks could be joined at this point and the quilt top assembled in the same manner as an "I Spy" quilt with setting triangles sewn to two opposing sides. Though... if you wanted to make half-blocks for the top and bottom of the alternating rows, that would be kind of a cool variation.
Because of the way I pieced the quilt top, I recommend not trimming off any of the little triangles sticking out until after you've sewn that seam. Porquoi? Because it makes a terrific guideline for matching points and pieces. You'll still want to check the junctions with a pin but the little triangle is an excellent starting point - as in, it was dead-on or very close to it for all of my seams. So as soon as the little point is in a seam, remove it. You don't need any more fabric in those seams than necessary.
When it comes to assembling the rows, there is some bulk at the centers of the block and those places where three triangle points come together. It won't be the easiest seam you've ever stitched but if you've pressed all the seams open and trimmed off the unnecessary little triangles, it shouldn't be the toughest either.
One last thing to mention, this block can be made using different backgrounds. Here's how it could be done: Cut three rectangles of each print. Cut three rectangles of each background. Piece each strip set using three matching background rectangles, two matching A-print rectangles and one B-print rectangle. That will yield three matching A-print triangles and two matching B-print triangles. Piece all of the strip sets required to make the quilt top and trim the triangles. Then, when you join the two "leftover triangles for the sixth triangle, pair the leftover background triangle with the leftover B-print triangle to make the 3rd triangle required. Trust me. It will work - and it will make sense when you do it.
(Just so you know, it used to make my Mom nuts when she'd hear me say "trust me" to folks. I think she only remembered the times I'd said that to my sweet brother as I led him into some ill-advised "adventure".)
If you have any questions about Hook, please don't hesitate to ask. I've always believed that when it comes to patterns, I led you into this "adventure" so it's my job to make sure it doesn't turn out to be an ill-advised one.

Okay, a second last thing to mention... if you would like to use a different fabric for your alternating triangles, setting pieces and borders, you'll need 3/4 yard of background and 1 yard of "alternating" fabric.
I'm off for now. I've got some more little quilts to finish so they can go for photography this week.
Toodles.