A gray clear is still a clear, and wanting to improve is a great thing. To add to Sebazy's suggestions, I'd get a good idea as to what your average ping looks like. As long as it's not 200+ (in which case you'll need to make adjustments for lag), getting good at slidecasting is a huge boost to GCD maintenance. The VAST majority of AOEs in this game go off slowly enough that you have time to finish a cast you started before it appeared underneath you, then move out while slidecasting the last 20% of your Broil instead of canceling it. It seems scary at first, but as long as you didn't begin the cast after the AOE appeared, you're *usually* fine.