How to use less data on Android (Gingerbread)?

[john]

I have a Samsung Galaxy Ace on Gingerbread. I am changing my plan to a plan that includes 200MB of data each month. I am junior at highschool, so I am mainly at home, at school, or at some other location. At home, I have WiFi, so I am set. In highschool however, our school's WiFi is a bit strange and doesn't work very well, so I won't be using their WiFi but using my data. Then obviously at some other location, I will attempt to use WiFi when available.

I will not be streaming videos or downloading anything with my data. Most of my data usage will be social networking (Facebook, twitter, tumblr), web browsing, and photo uploading (Instagram, etc.) Will 200mb be enough?

Also, what are some tips on how to use less data on Android devices? I heard people said to use Opera as a browser because it compresses the data. What other tips are there? Thanks.