Not hard at all. Just grab a big bunch of non related fabrics, with a bunch of different colors, use a lot of different colored threads, lace, buttons, sparkles, embroidery, ric rac, applique, anything that catches your eye.
And that is CRAZY quilting. I've never heard of anyone actually using one as a real quilt, it's more of a show piece but is almost always a lap robe. In the 1800s it was a fancy piece that the lady of the house did to show off to her friends, to prove that she was wealthy enough to have servants so she could sit on her butt and do fancy work.
One lady on this forum last year showed a picture of a full sized crazy quilt she sold for about 70 grand. I was ready to have my eyes checked...but that was the correct total.
Have fun with this, and relax, it'll work out nicely. You don't have to measure fabric for it, you don't have to match it with anything except your own imagination.