Some very popular tobaccos come in the form of a cake, flake, spun and rope. Preparing them for smoking is an individual thing, but here are some guidelines:
Preparing a cake tobacco for smoking
These tobaccos are cut tobaccos that have been put under pressure, and are normally sold in slices. The usual way to ready them for the pipe is to break up the slices in your hand. The main thing to consider is how small you want the pieces to be. Breaking the tobacco up finer will give you more flavor, but it will burn hotter. Larger chunks will release less taste, but the tobacco will burn slower and cooler.
Preparing a flake tobacco for smoking
Flake tobacco is similar to a cake tobacco, but pressed from large leaf, and usually sliced a bit thinner. Many people prefer to just bend a few flakes and stuff them in the bowl, topping it with some fine pieces to get it lit easier. This will result in a cool smoke, but may require more maintenance while smoking. They may also be prepared the same as a cake (above).
Preparing a spun cut tobacco for smoking
Preparing a rope cut tobacco for smoking
For more specific information about the processes used to make these tobaccos, read my tobacco processing article over on PipesMagazine.com here.