I have yet to actually use a pattern per se. Just tend to play it by ear and do my own thing. It is nice to have the dimensions of the pieces in the block you're doing spelled out in EQ7 however. And of course I've modified the block from the 'stock' block anyway...and it still comes up with the dimensions for me...whoohooo!
Patterns are just a starting point for me even in regular sewing. I'll take this from that one and that from another one and make it how I want it.
I tend to start with the fabric, figure out which ones play together nicely, what proportions I want of each, how big the focal fabric needs to be, then go from there.
So far I haven't done anything with little bitty pieces (smaller than 2-1/2" squares or 1-1/2" strips) except for playing around with scraps and sewing them into strips for future use.