i saw a vid on youtube of someone applying fondent and the cake was nice and thick and flat, also shop cakes are. but my cakes are always go rounded at the top and the sides are straight either. its hard applying butter cream to the edges also

also do i put butter cream as a glue for the fondent icing??

and i wanna stick shapes on , how do ido that??

also when i put the jam and butter cream in the cake the cake tends to slide around.

I don't know if this is going to help or not, but when I take my cakes out of the oven, I invert time on to their tops. Then I put a piece of parchment paper on the bottom of the cake, sit the bottom of the pan on the bottom of the cake and them I weigh it down with a can of some kind of can good.............lol, I know it sounds funny but since I have been doing that, I have never had to trim a cake.

As for the butter cream under the fondant...............it is a must, it helps glue the fondant to the cake. You said that you wanted to stick shapes to the cake, well there are two ways that you can do that. You can stick them on by painting the back of them with some type of extract, don't use water.............it will never dry, the extract has alcohol in it and it allows it to try quickly. The second way it to use royal icing on the back of each shape, you don't need much, it doesn't dry out as fast as extract but it words great for larger pieces.

When I took my wilton classes, they told use a fairly large, but not huge round tip and pipe a damn about an inch away from the edge of the cake with stiff to medium butter cream and them fill it in with anything you like, as long as it wasn't too thin. I tried it with cherry pie filling to make a black forest cake and it worked great.

I hope this helps..................let me know if any of it worked out for you.......I know my method of flattening a cake is a little strange but it works great for me, I can never seem to trim a cake evenly. Good luck!

if your sides arent straight, surely that is a problem with your pans? you will just need to carve them to get them straight.

you can get a more level cake, by using bake even strips round the pan (lots of posts on them if you do a search), put a flower nail in the bottom of the pan, helps conduct heat. you can press the top flat right away when it comes out the oven too. but a lot of times, you will need to carve a little bit.

it is best to coat your ckes in bc before applying fondant, but how much is up to you - some people just crumb coat, some put on a full layer. you can just use jam, but then your cake needs to be really perfect, as all bumps will show through.

most people do stick shapes on with water. you can use vodka, edible glue, bc, royal. i use watever is hany, ie: bc from coating the cake lots of times!

how thick are your fillings? it can help to chill your cake so that the filling sets up, less sliding. a dam is the best method, but for unfancy family cakes, i dont bother.
xx

Hi and Welcome to CC, yodofrodo.

Decoding CC acronyms:

http://www.cakecentral.com/cake-decorating-ftopict-2926-.html

Everything you need to know to make, decorate and assemble tiered/stacked/layer cakes:

http://www.cakecentral.com/cake-decorating-ftopict-605188.html

HTH