A 16 patch is a patchwork block made up of 16 squares. Here I am using only two fabrics.
To make these 16 patch blocks I started off with 2.5" strips. I cut mine with a rotary cutter on a cutting mat but you can use a jelly roll which is much easier. They need to be very accurately cut. The strips were at least 10.5" long. I sewed them together as shown with 0.25" seams.
I then ironed all the seams to one side as shown here.
I then turned it to the right side and trimmed off one end so they are all exactly level, and then cut 4 strips each 2.5" wide. You probably have a spare bit left over. Put that to one side to use for... something.
Then turn two of the strips up around.
When you turn them over you can see that where you ironed the seams down they now go alternate sides. This means that you can nest them together to get your corners exactly right and perfect.
Then sew them together using a 0.25" seam.
Then on the wrong side, iron all the seams to one side and turn over and iron on the right side.
Ta Daaa! You now have a lovely 16 patch block with all the seams lined up beautifully! Well done, you are amazing.