These days I keep very few bookmarks in Firefox. There are a few there for sites I visit every day. The rest are in del.icio.us so I can access them wherever I am. Even for sites I do have in bookmarks I quite often access them by just pressing F6 and start typing the URL. One problem with this is that my history has quite a few URLs that I have mistyped. I used to think you could only get rid of them by clearing the whole history, but I recently read that pressing Shift-Del would clear one. Not only that, but it works on web forms too for text that Firefox remembers for you.
I've had some issues with my right hand due to using the mouse so much, so I prefer to use the keyboard when I can. Lots more shortcuts for Firefox here. I should try and learn a few more, taking account of the differences on Windows and Linux. If I am using the mouse I like to use mouse gestures as this reduces the number of clicks required. There's a few gestures I use, but again I ought to learn some more.
The general problem with all these shortcuts is that you don't always realise that they are there unless you read the documentation, and who does that? Another recent revelation was KDE's Katapult. I now use that a lot for launching certain applications.