Anyway, if you're somewhere where there's a lot of static (carpet, dry, etc.) you may want to get an anti-static wrist strap.. they're only like $5. Clip it to your case, and you should be fine.
However, most people will just tap their case every once in a while (make sure to tap/clip to the metal part) to ground themselves. Do it often, though you don't need to constantly hold it. Make sure static bombs (pets, children, especially furry cats...) don't get near your workspace. Don't set your motherboard on the anti-static bag it came from, set it on top of the cardboard box it came from. Always ground yourself in between working on the motherboard and doing something else (say... opening a box).
I do advice on using a PSU plugged to the wall (switched off) and touch it every now and then, as it helps you ground, or put the psu on the case and plug it to the wall(switched off) and touch the metal part of the case