How do you get those beautiful sharp edges when you cover your cake in fondant? My cakes always end up looking very rounded at the top. I am assuming this is because the buttercream is too thick around the edges of the cake? I have seen on some youtube videos where the cake is barely coated with buttercream, there are parts where you can still see the cake. Then they cover the cake in buttercream. Then I see other videos where the cake has been crumb coated with buttercream then coated again and smoothed. I am not sure which way to cover my fondant cakes.
Seems everyone does it different. Some people use very little buttercream and others will put a thick layer on before covering with fondant. You just have to practice and figure out what works best for you.
What works best for me is to make sure you chill the cake well after icing it. That will make the buttercream more firm and won't smoosh so much under the fondant. Use two smoothers to sharpen the edges.
But the thing that works best for me is to use ganache under fondant. That gets much firmer than buttercream and I can get really sharp edges when I use it. This thread is long, but very helpful!
Also try to make sure your fondant isn't too thick. There's also lots of good youtube tutorials and threads on here that are very helpful.