Being a developer i noticed that my firefox consumes lot of memory once it was started. Few of the points may be helpful for you to keep the memory little free –
- Hide the bookmark and web developer toolbar as use not quite ofently using these. (try to use shortcuts for that ctrl+b for Bookmarking and F12 for web developer tool).
- Restart your browser with add-ons disabled and check memory consumption (MENU -> HELP -> Restart with Add-ons disabled).
- If you are heavily using the add-ons try to uninstall and remove the unnessary add-ons/plugins.
- You can also edit “session” options in Firefox, only if you understand the technical risks.