No raft, I start immediately with the first layer of the model. Works pretty fine for me.
For largish models, e.g. for the sections of the Sky Reaver, I use a large brim (20mm), but I think that is mainly a problem of my steel platter. Same goes for the Gloomwood Trees, they simply don’t want to stick, so I print the brim, and after 5mm or so of height, I use some blue tape to make the brim really stick to the platter.