The guillotine press – where you bring the bar down to your neck instead of the lower pecs – is a great chest developer. But there is risk. Keep these light and under control. This is not a bench press variation to go heavy on. And don't try to set a PR! This is bodybuilding, not powerlifting.
My favorite way to use it is 6 x 6 with 20 second rest periods between sets.
It's probably the simplest training method imaginable, but it's oh-so effective in promoting shoulder stability and building power and strength. All it takes is a minute and thirty seconds, three times a week.