Do you guys have any 'game tactics' that you follow in every game? If I had to pick one rule, i'd say mine is: If given the chance, do the hard part first.

Wow I dont do that. I guess I dont really have any gaming habits. It really just depends on the game itself.

 Actually, I think, If given the chance, do the easy part first so u can build up to it and u won't get frustrated as much. For ex, what if u were given the chance to fight Bowser first in SMG. U would prob. completely suck cause u haven't built up ur skill yet

Power ATK
over
Defence

No, I don't I find that every game has a different tactics.

Always save at every checkpoint if possible

I tend to save all my items in games, in case of "emergency" and then I finish the game without using them, which seems like a waste to me.

Dodge often, never use items unless they regenerate themselves or unless absolutely necessary to do so

Save as often as possible.

(I started doing this when playing pokemon. My pokemon could be kicking ass, then Gary shows up and almost kills them. I have to travell all the way back to the nearest town to heal, and work my way back. Or I simply die and lose evrything I worked for! Saving is a must!)

Save early and often (except in the early Resident Evil titles, or others where you have limited saves).
Also, I generally save in more than one file in case one of them gets corrupted, that way I don't lose much of my data.
I also try to do as many sidequests as I can early to get better equipment/characters (in RPGs).
Use as little ammo as possible (in shooters).