Recently introduced to Vimperator, an addon for Firefox that makes Firefox more like Vim, which is amazingly useful for keyboard-based browsing. Nothing like being able to navigate pages from the home row (unei style for Colemak, with a bit of remapping). Try it, but because it completely mangles Firefox's keyboard shortcuts and some of Firefox's UI you may want to try it in a separate profile first.
Which is my second trick: Firefox Profiles. I used to think these were a vestigial organ from Netscape used only by corporate types. Then I realized that I had two good uses of them and that shut me up. First I've become one of those people that have an extremely long running session and keep something around 10-20 tabs open that come back when I relaunch Firefox. I actually find that useful, but there is one scenario where that becomes an issue: roaming wireless. Many wireless networks have "welcome" or "sign-in" pages that redirect you on first connection. I created a "clear" profile that opens to a blank page specifically for unknown wireless networks where I want to wait to pull up my long running session until after I know they won't be redirected. The other use is that I decided to move my addons like Firebug and YSlow to a separate profile to keep them from taking up memory when I'm just surfing.
To set up a new profile run firefox -ProfileManager which gives you the normally hidden profile GUI. To start Firefox with a different profile you can create a shortcut with firefox -p <profile-name>.