Use the Motorcycle Safety Foundation's T-CLOCS checklist this, and every time you ride. The list covers Tires, Controls, Lights, Oils & Fluids, Chassis, and Stands; for a more detailed checklist, go to the MSF's website.
Don't just take off after a thorough inspection; let the bike idle for a few minutes to get its fluids circulating.
Take those moments to get reacquainted with the bike's ergonomics. Before you go riding off into the sunset, don't forget that the most important component of a motorcycle is you, the operator. If you suspect you're rusty (and there's a good possibility you are), practice riding in an abandoned parking lot, taking it easy until you're up to speed.
When all is said and done, a little preparation will make re-entry into riding a lot more fun; look out for yourself and your bike, and enjoy the ride!