Are you talking about the normal tin can framing for walls? To pull cable or pipe through?
If so, and you plan to be doing a lot of it in your forseeable future, get a stud punch.
Otherwise holesaws and unibit will work, but much slower going. Just remember safety glasses and long sleeves for all that hot flying metal. $200+ for a punch will pay for itself fast, on even one job. 10X faster than drilling all the holes. (You will still have to drill a few.)
If you're talking about heavy gage, red or black iron, go for carbide hole saws.