All you need to do is KEEP practicing. The more you do, the better you will get. When you look at many of the gorgeous cakes with flawless fondant, you are also looking at a huge variety of:
homemade or commercially prepared fondant?
what recipe homemade?
what brand commercial fondant?
buttercream under fondant?
marzipan under fondant?
chocolate ganache under fondant?
how thick is the under-coat of buttercream, IMBC, SMBC, marzipan, ganache, etc.?
mud cake, fruit...