I just came to the board to ask this very same question. Yesterday I was making a fabric "box" and the fused side looks wrinkly today. I've made a couple of purses using the same fleece and they don't look wonderful (I didn't want to quilt them).
My arms ache from pressing down so hard on the iron (I set the board down very low so I could get a good weight on it) and I used steam, wet presscloth (like my instructions say) and did everything twice, then went over it all again with just the iron on both sides. Each time I left it to cool completely before I touched it.
Just sign me "fed up" - I have two new purse patterns I'm dying to try, don't know what to do - guess I'll have to quilt them.