My compost bins do not smell. I make sure that there is a good mix of stuff going into the bin.
If yours starts to smell, short term fix is to put a layer of lawn clippings over the top. Long term, make sure there is a balance of vege scraps/lawn clippings/leaves etc and turn over once in a while.
The most likely source of smell is aneorobic (no oxygen) rotting which produces methane and things like hydrogen sulphide. What you want is areobic rotting (with oxygen) so turn ove the compost occasionally and ensure that you have holes in your compost container to let air into the heap.
On the other hand you don't want too much ventilation that your heap dries out, so it is good to have solid walls with holes/slits in to let some air through.
For example.. The wetter your climate, the more holes you should put in.