How do bakers get they cakes to look smooth?

Well first of all you need to have a particular shaped -out icing spread and if you watch many ADS (advertisments).You can see they always will say about icing spreaders.

Cover the iced cake with a sheet of wax paper and smooth it out with your hand. Refrigerate the cake for awhile and peel off the wax paper once the icing has hardened. You will know it is ready when the icing does not stick to the paper.

Another way to have the effect of smooth icing is to use fondant. It is like dough, but it is made mostly out of sugar and its easier than trying to get icing smooth..