One thing I always try to press on my female clients is the benefits of load bearing exercise (weight lifting razz ) it does burn calories, you WON'T get a big musclular guy's body (any of the guys here should agree, we have to work SERIOUSLY hard to get it, and we've got genetics on our side!).
And also, major added bonus, it drastically reduces the chance of Osteoperosis later in life by strengthening the bones (which females are far more prone to.)

I'm only referring to females because I've never had much trouble convincing guys to use weights lol. Don't want anyone to think I'm being sexist here.