If you wanna play low, for one don't go overboard- if your guitar is below your waist, that's a bit much, and too much strain on your joints as well. But your guitar angle can help a lot too. I play with my guitar pretty low. When I'm playing rhythm, it's at about a 45-degree angle, but when I play leads, it's more like 60 or 70, closer to being perpendicular with the ground. It makes it a lot easier to play leads with you sling your guitar way low.