For the life of me, as many times as I have tried, I cannot get fondant to look smooth. It always looks lumpy and has air pockets. I've tried using a toothpick to let the bubbles out, but it still looks lumpy. Also you can see the cake layers through the fondant. Very disheartening!!! I just don't know what else to do. Help

what kind of fondant are you using? do you make your own, if so, which recipe. I really do like MMF, i think it is very easy to use. i knead and roll it out until it is very soft and smooth. I feel that makes it easier to work with. It makes it easier to roll it out, to cover and then to smooth it.
I am not a fondant expert, but that has worked for me.

HTH

Use a firm cake underneath.

I trim the sides to make them straight; us a crumb coat of BC ( if I use a full coat it looks all squooshy). I chill the cake before covering it to make putting the fondant on easier.

make sure your fondnat is not rolled too thin; go about 1/4 inch thick until you get more practice and then you can go a tad thinner.

HTH