What part of these projects is hard to make fit?

The Twisted Sisters Knit Sweaters: A Knit-to-Fit Workshop

I've looked through my copy several times now, and I'm just not seeing how hard it is to make these kind of things fit.

The Dolman, batwing sleeve thing kind of fits a pretty broad range of sizes doesn't it?

As far as I can tell, all of the designs in this book are pretty forgiving in fit. I was hoping for hints on how to make things really fit. Not that my figure is worth showing off at this point in time. But, I knit for people that have it and should flaunt it.