Principles of Chess

What type of Principles do you go by? And any other type of Principles you know about? I know some for opening and endgame like do not move a piece twice, or if you do have a good reason, and the rook belong passed pawns and passed pawns should be pushed, and some other like trade down when up material or up in space(I think this one's wrong oo) or don't trade down  when less space. And the rook, bishop pawns are usually draws in a q+k vs Rp/Bp+k and knights pawn usually are won/lose(depending). I sometimes go around the principles like bending the truth for a position. Anyways. What types of principles do you know?

the one taught to me was

....you are not yet to commence any plan if you're two rooks are not yet connected....

....strive for the center squares..

....overprotect your center(from nimzovich)

Keep your king well protected until the endgame then make him active.

be aware of your opponent not adhering to any of the above (they all sound good to me) and then be prepared to exploit those weaknesses. A simple example would be if someone moves their queen out to early, another no no, if possible keep attacking the queen and all the time you will be developing pieces and gaining momentum while your opponent will be wasting time protecting his/her queen that has come into the frey to early.

1. Look for tactical threats and opportunities. This trumps all other principles.

2. Use your whole army. Develop quickly. Coordinate your pieces to work together.

3. Control (or at least get equality in) the center. Then pick a wing (kingside or queenside) to attack.

4. Create space for yourself and be alert for the chance to cramp your opponent. If your pieces are cramped, look for ways to attack whatever is limiting your mobility.

5. Be very, very careful about opening files or diagonals that expose your castled position. In general, don't do it unless you are attacking (and confident that it won't backfire).

6. Know when to exchange: when you have a material advantage, when you are defending against an attack, when you can disrupt your opponent's pawn structure. Know when not to exchange: when you are preparing an attack, when you are behind in material, when your opponent can develop a piece in recapturing. Rule #1 is especially important here, so be prepared to ignore these rules of thumbs if a winning tactic is available.

Good advice Pegrin. I thought I would acknowledge this because too may times people like you spend time and effort helping others to improve their game and they simply read and not comment. So - good on you!