If it's flat hit the chip for what it's rated.
In other words, if you have 10 yards to hole, hit your SW (or whatever is closely rated for 10yd).
The problem people get themselves into is trying to chip with 7-irons and 8-irons and using half of the meter. In real life, that's a bump and run and is a nice tool to have in the bag. However, in this game, you can't use the meter that way for chips or pitches. Anything less than 50% or 60% will most often give you a bad result.
The other thing people forget is elevation. If you're chipping to a pin that is above the ball, then you need to know if the green is flat or not. A lot of times you're chipping up a hill to a flat green. The ball lands on the green with a much lower trajectory than normal and thus, rolls much farther than anticipated. Watch out for the elevation change and note if it's a gradual change or an instant change. Check the slope of the part of the green you're landing on as well to make sure you're not chipping into a downhill or uphill slope.
Practice makes perfect. :)