I am having trouble smoothing my bc.. I use a little roller and I roll it in cornstarch and powder sugar but my icing keeps coming up...

if you are using a crusting buttercream, wait a few minutes until it crusts and then use a plain viva paper towel on top and smooth gently with your hands. hth

Do a search here there are a lot of threads on this subject. My very best advice go to youtube and watch tonedna tutorial, and/or get Sugarshacks video. They are the best!

http://www.youtube.com/watch?v=iqvL4zhVbE8&feature=channel_page

This woman has several more excellent tutorials on youtube. I've learned soooo much from her!