Partitioning advice

I'm about to organize the hard drive on a new system and I'm looking for advice about partitioning it. The question is: which Linux partitions should be separated out from the root partition? Candidates are /boot, /usr, /var, /home (that one for sure), /tmp, and /usr/local. I can probably make pretty good guesses at the appropriate sizes by looking at my existing systems. I know this question has come up before but I haven't been able to retrieve the answers. Paul