Emacs productivity tips

does anyone have any emacs productivity tips?

is there anything that you've done to your emacs to make it work really well?

im using gdb inside of emacs, i type M-x compile to make, i only use emacs -nw inside of terminal because the regular X version is too slow, stuff like that...

i've never used buffer rings, or customized keyboard shortcuts to automatically macro-out if statements and stuff....

im joining a startup soon, and want to get more efficiency out of my coding! :)