When the primer is dry, caulk all small joints (less than ¼-inch-wide) in the siding and trim. Most pros use siliconized acrylics—paint won't stick to straight silicones—but Guertin and O'Neil like the new, more expensive urethane acrylics for their greater flexibility and longevity. O'Neil stresses that it's shortsighted to skimp on caulk. "If the joint fails, you're back to square one." Guertin uses the lifetime rating as his quality guide. "I don't expect 35-year caulk will last 35 years, but it should last longer than a 15-year caulk."
As a former professional painter, something that drives me crazy is when I see painters cut in around wall plates. First of all, the amount of time that it takes to cut in is usually much longer than the amount of time that it takes to simply remove the wall plate. Secondly it does not look nearly as clean as it does when the wall plate is removed and thirdly it can invariably leave paint on the wall plate itself which also looks sloppy. Make sure the painter takes them off and then reinstalls them. It's less time.