Sheepskin pads stay cool in hot weather and warm in cold weather. They breathe, they're washable, and they're available in different colors and sizes, according to Jamie Elvidge, writer for Motorcycle Cruiser. Choose a pad that's easily adjustable.
Fabric cushions with a polymer gel pad inside can be cooled or heated before a ride. Look for one that is easily removable. The problems with gel pads are that they don't breathe that well and can be rather heavy.
At the top end of motorcycle cushions is the Airhawk, which costs a few hundred dollars. It consists of air-filled cells made of neoprene and has a valve that allows the rider to inflate and deflate the pad. The Airhawk breathes, is waterproof and has a two-year warranty. The wood bead pad is at the other end of the spectrum, costing under $20. Still, it allows air to circulate and has a massaging effect.