Hi DJ, I use satin ice and yes I agree, even if I think my cake surface is smooth as glass, the satin ice will somehow manage to find a minor imperfection to bring the most attention to. I never use buttercream under my fondant because it always bulged underneath so I use ganache only. I roll my satin ice on a fondant mat (never on my table because the cornstarch or powdered sugar dries it up too much) and drape the mat over the ganached cake (room temperature but set overnight or several hours and brushed with boiling water to make it tacky and help it smooth out more) and peel back the mat and work quickly to smooth it over the cake. I roll the satin ice to between 1/4-1/8 inch thick and that works well for me. Some might think its too thick but my clients haven’t complained. Once the fondant is on the cake, smooth smooth smooth with your fondant smoothers – go round and round the cake, I am usually able to smooth the imperfections away with this method. But for starters, try to smooth your buttercream more, even if you think its perfect, try smoothing just a little bit more – perhaps dip your spatula in boiling water and go around the cake. Good luck and I hope I was some what of a help.