Pick some scraps of various sizes and widths. They don't even have to be ironed! I am doing just one (kind of) color. You can do it the same or mix them up.
Take a piece of any size, at least 2 inches, and trim it to have 4 or 5 sides. The one in the picture has 5. I find the 2" size is a good one to try this technique. Bigger is even better as you will see later on.
Take another one of your strips and sew it to a side, any side. Seam allowance does not matter, edges do not have to meet.
It will look sort of like this......I did not even trim the threads.
Add another strip, again any side it does not matter. See that polka dot strip it's wrinkled!
and another......and keep going until you are happy with the size.
This is where the bigger center can be better. After you have sewn a few more strips of fabric, take your rotary cutter and wack it down the middle or on the diagonal. You don't have to use a ruler but you can if you want.
I took another strip and sewed the 2 pieces I just cut to each side of this strip.
Occasionally I stop and press the block. I like to add a little spray starch as there are a lot of bias edges and you don't want to stretch them. This also lets you see how big the block is getting.
I made my pieces about 6 to12 inches or so and then I started sewing the different pieces of made fabric together. In this picture you can see the line where the two meet.
As you go along stop and straighten your edges from time to time. They don't have to be square, just make them straight so you don't get lumps and bumps. Save those corners you can add them to your fabric you are making!
I even took strips and sewed them together and then sewed them to the block so I did not get one long piece that might stand out.
When you have enough pieces to make your fabric the size you want trim the ends and just use your rotary cutter to clean up the edges. Be sure to press all of them with the spray starch. Next lay out the pieces you made and see if there is a logical way to put them together. This is kind of like putting a puzzle together and there is no right or wrong way. You may end up trimming you blocks even further to make them fit together.
This is what mine ended up looking like....I know it is a weird shape, but I do have a plan! It is about 30 inches high from top to bottom, if that helps.