Here are useful some Mass Effect 2 Tips and Tricks for both beginners and veterans of the game:

1. Endgame will force mining, so you might as well do it early.
2. Use cover a lot.
3. Shields aren't the best protection.
4. Enemy AI will flank you more often than in the original Mass Effect, so be more aware of your surroundings.
5. Make sure you make room when you "throw" your biotic powers.
6. Make sure your squad knows how to deal with different enemy types.
7. Squad AI is prone to getting hit by rockets, make sure they are behind cover.
8. The Sniper Rifle is very useful, use it!

Please help contribute to the list by submitting your own Mass Effect 2 Tips in the comments below....