First I lay all the strips out on my cutting table the way I want to sew them together. Usually this is a light-dark-light arrangement. Even though the strips may be different lengths, keep one edge even - like the top of a picket fence. (In my first picture there is one big jog because the ends of the strips weren't angled the correct way. This just makes the cutting trickier.) I first sew them into pairs, then into sets of four, and so on. I make my sets as long as my cutting table, because the longer the set the more squares, as the two edge strips have left over triangles instead of squares.
The most important thing when stitching the strips together is to make sure you aren't stretching the bias edges. Press to the dark as you stitch things together, unless you are cutting squares 1 1/2" or less. When they are that small I like to press the seams open. Once they are all together get our your square ruler and rotary cutter. Align the 45 degree angle line with the seamline and make the first two cuts, which will separate the square from the strip set. Working across the bottom of the "pickets", cut a square from each point. This gives you a new set of points, which you then cut into squares working in the opposite direction. When you have cut all squares you can, then go back and trim the other two sides of each square for a perfect half-square triangle square. You can get a special ruler designed just for cutting these squares, but it isn't necessary.
You will have some pieces left at each long edge that are sort of triangle shaped. Stitch these together on the bias edge and you will be able to cut a few more squares.
The rule of thumb is to cut your strips the same width as your unfinished square - 2 1/2" strips for unfinished 2 1/2" half-square triangle squares. I've found, however, that when the squares are little it's best to cut the strips about 1/8" wider and when they are bigger you can cut the strips 1/8" narrower. Once you are cutting bias squares larger than 4 1/2" square this method is no longer efficient. At that time I just cut squares, pair them up right sides together, and cut them in half diagonally. Then I stitch the cut edges together to form the bias square.
When I need just a few bias squares from each fabric combination I cut large squares from the fabrics rather than bias strips - 6", 7", 8", 9" or 10" squares, depending on the number of bias squares that I need. Then I cut each square across the diagonal, and cut each half-square into appropriate width strips. The last two cuts give you two triangles that you can stitch together for a final square.
There is a small amount of waste with this method, but because of the total accuracy of the method it's a fair trade. I used to save the small waste pieces for paper piecing, but not any more. And I find they don't work for crumb squares because they are sort of diamond shaped instead of square.
So that's what I've been doing these last few days instead of posting. This weekend I must finish the wedding quilt for my friend, and I hope to also finish piecing the Broken Dishes.
Then I think I'll make some Mile-A-Minute blocks from the plastic boxes of crumbs and odd-sized bias squares that I've found!