you don't say what pattern you are making. However, let us assume you are sewing the three strips and then sub cut into squares.
If this is the case, then: Stack the jelly roll up and cut in half.
Take the top of the right stack and put it on the bottom then select from the two stacks three strips and sew. Set aside. Take two from left side and put on bottom and select three 1/2 strips and sew and set aside.....continue this pattern which will mix up the strips. Then you have scrappy.