I also treat the roving like a little bird or butterfly that I don't want to crush, so the fiber is just resting in my hand (in the crook of my pinky, actually...) and not being squeezed.
Also you could split the roving lengthwise into skinnier pieces -- some roving seems to want to split, which can cause segments to bunch up behind your hand while one segment alone gets drafted. That way, there's less width to draft across, too.
If the fiber started out matted, there are two things you can do to help unmatt it. First, break it into 1-2 foot lengths and "crack the whip" with each piece from each end -- the snapping tends to open up the end. Second, predraft the roving -- even if done just a little bit, this helps start the sliding process of drafting so that when you spin and draft, it drafts more easily.

For related entries, see:
Do you pre-draft your fiber before you spin?
How do you go from spinning fine to spinning thick?
Do you have a spinning or sock machine question for the belle? post it in a comment on the blog or contact me. Thanks!