To keep a mattress from sliding around on its foundation, put a nonslip rubber mat between the two.
To even out the wear, turn a new mattress over and reverse it end to end every 3 weeks for 3 months-and every couple of months thereafter.
Don't use the handles on the mattress to lift it. They're not designed to take the full weight but only to move the mattress around while it's on its base.
Air a mattress in the sun occasionally to keep it fresh and clean smelling.