Buff smart: use SmartBuff. This addon is pretty comprehensive and crazy configurable, and is designed to facilitate and partially automate the buffing process. Here's how it works:
- Check off which buffs you want to keep up, on what classes, main hand/off hand (if applicable), and when you want it to remind you (in combat, out of combat, 10 seconds remaining, etc).
- Under the specified conditions, SmartBuff will put a reminder up on your screen (also configurable, of course) telling you who needs what buffs.
- Now simply click the SmartBuff button, or scroll your scroll wheel (if you have that option set), and the necessary buffs will magically be applied for you!
It doesn't get much easier than that. SB also supports setting up profiles, for PvP vs. raids vs. parties, for instance.