If you are bedridden, reposition yourself every couple of hours. If you can't, the staff should - a couple of hours on your side, then back, then other side. Repositioning is often a neglected task by busy nursing staff. Barrier creams, sheep skin pads, and egg crate mattresses can prevent bedsores. If that lower back and coccyx starts looking red, be vigilant.
Prevention is a heck of a alot easier than healing a bedsore.
Offering a variety of fluids, especially juices. Weighing the patient daily. Providing cups and pitchers the patient can handle. Oversize cups with built in straws is one idea.