Portage: Basic compile time customizations?

[ThinkBayon]

If I'm going to spend time compiling apps via portage, I'd certainly like them to comply with certain specifications. What are some beginner compile-time customizations for Portage? Are there certain parts of the application that many choose to leave out? For example, documentation? I'd like to recompile many apps in 3.4, but if compiling is done "vanilla," it's going to take ages and give me less benefit overall.

[flick]

An excellent, well-commented example make.conf file is at : http://gentoo-wiki.com/Make.conf.example

Reading through that, following links in it, reading those, etcetera, are what got me to ( minimal ) competency at tweaking /etc/make.conf

Hope that helps!