If you grab the BF3 Settings Editor of the main page here are some good things to tick/slide/you get the idea.

Gameplay Tab

Network Smoothing factor This is entirely dependent on connection mine is set to 0% Anything over 20meg, I think it's OK to turn this down to 0% If you start to see rubber banding in the game move the slider higher.

Graphics

No major ones here though I would advise the following

Vertical Sync Unticked
Colour-blind Support Ticked Changes colours of enemies and team mates, makes it far easier to spot.
Brightness 100% Light up the dark
Field of View 90 Enables you to see far more of the game without fish eyeing.
Motion Blur Amount 0%

Console Commands

DirectX 11 Unticked. Does not alter look of game but gives you FPS
DX Deferred CS Path Unticked. Does not alter look of game but gives you FPS
Triple Buffering Ticked.
Draw FPS Ticked.

Fixes

Some very useful fixes to BF bad key mapping in game. Fixes the q re-bind issue plus a few others.


Grab the download HERE