Most golfers overthink their short game and take away from their own natural ability to chip the ball close to the hole.
Set up 9 golf balls in different places around the chipping green, try to vary the distance, amount of green to work with, and amount of slope on each shot (the more variety the better). Once you have your balls set up the aim is to chip each ball as close to the hole as possible and move as quickly as you can to the next shot, playing each shot as soon as you get into position without taking a practice swing or taking large amounts of time to line up. It will be quite difficult the first few times around but once you start to get out of your own head and play each shot more re-actively you will notice how easy it can be to chip without thinking about it.
You could add to this by carrying a putter and quickly walking onto the green to putt out each ball and even time yourself to get all 9 balls into the hole. This drill is also a great cure for the chipping or putting yips
The less I think, the better I play!!