I'd say that if you're finding you always have work, or rather, if you have enough work, then you don't need to worry about turning away clients due to being to

I'd say that if you're finding you always have work, or rather, if you have enough work, then you don't need to worry about turning away clients due to being too busy. As a consultant, it's a good thing to have to turn away work. You should also consider sending clients you turn away to another consultant. The idea is that when you're really busy, you send "overflow" customers to him (or her). And the other consultant would ideally return the favor as necessary.