For two more ways to piece HSTs, check out Piecemeal Quilts.
My first (and honestly, long abandoned) method for HSTs is about as traditional one can get, short of fashioning templates out of cardboard and drawing the shapes out onto the fabric back. Thankfully, due to rulers and rotary cutters, we don't have to go quite as traditional as we could:
First of all, some basic math - or the 'magic number' for Half Square Triangles:
That's it. Add 7/8" of an inch to the desired FINISHED size of your HSTs. In today's case, that means that our starting squares should be cut at 3 7/8" by 3 7/8". Notice the words 'should be'. I'm not, nor will I ever claim to be, a perfect cutter. Mistakes happen. I personally add at least the 1/8" needed to bring it to an even number, and trim down. I add more leeway if I know I've got the extra fabric. So, go ahead and cut two squares each of your light and dark at 4" by 4". In my case, I cut one square each of the two prints, and two squares of the dark brown solid:
Pair up your light and dark halves and sew them together. Be careful! You are now sewing on the bias edge - this means that the fabric can stretch, so do your best to not pull the fabric. Just let the feed dogs take the fabric as naturally as possible.
Cut a 4" X 16" strip each of your light and dark. In my case, I cut two strips of each of my prints at 4" X 8", and two strips of my solid at the same size.
Then cut along the diagonals:
From here, continue on with the finishing steps from the first tutorial above... Press your new squares open, and stitch your pinwheels together. Having done both methods here, I think you'll see, easily, why I prefer to stitch my HSTs in strips. I'm not piecing on the bias, so there's less distortion. I'm not chain piecing so much, and seams are far more accurate this way.
If you've followed Sandi's tutorial, here, then you'll have four 3.5" pinwheels that you can make into a 12.5" block. My block: