Hey all! I'm new to cake decorating and have done a few practice cakes for an upcoming event, but every time I lay the fondant and smooth it out I can see the lines separating my layers. As if that's not bad enough the top of my cake never stays completely flat! So my question is, how much buttercream am I supposed to apply? Should I leave it just a crumb coat? If not, how much buttercream needs to be on the final coat? Or what do you think I'm doing wrong? Please help!