So, your best bet in general is a global look at the game, where you can attempt to optimize as much of it as possible. Here is a great post that still holds up on Basic Overall Optimization
Utilizing the MicroProfiler will enable you to target those areas in your game that need the most work. I’m sure you’ve already seen these as well, but just in case you haven’t give them a review.
Improving Performance and All These Guides
I wish you the best of luck. 