Byron Hamby, an instructor at my home airport, was named CFI of the year in 2007 by the FAA's Allentown, Pennsylvania, Flight Standards District Office. I talked with him about how best to shake off some of the rust. His first suggestion (not surprising) was to book a session with a CFI. Actually, he proposes making that a good habit even if you are flying regularly, because bad habits can creep into your flying over time. A short ride with an eagle-eyed instructor can flag some of the shortcomings in your technique that you might not even realize are lurking beneath the surface.