1. TIME
When I say "time" I mean several things. First of all, take your time. Rushing into anything is a mistake and it will probably cost you. Take a deep breath, slow down your thinking. A rushed mind is a jumble and rational thought will suffer. Instinct is good, but without thought to guide it, you are little more than an animal. Slow down your brain. Relax.
The second aspect of "time" is simply time. Do you have the time needed to dedicate to the potential attack? Are you being rushed? If so, don't do it. You will suffer for it and potentially lose the engagement because of it. Rushing into battle only serves the cause of the enemy.
2. KNOW YOUR WEAPON
No matter how much hi-tech equipment and training a soldier carries into battle, a man can still be killed with a stone spear by an enemy that is better than him. In other words, it doesn't matter how many skill points you have, or how many previous kills you might have, that swarm of Rifters can still kill you. That T1 fitted Myrmidon can still take down your ship if you are not prepared.
How does this relate to Eve? I'll give you an example. I hate flying ships I am not familiar with, ships that I've never flown before or that are fit in ways I've never fitted a ship before. That isn't about one Interceptor to another, or one gun boat to another - those tactics are similar - but about a completely different mind-set. In those cases I like to get my practice in with Corp m8s, take it out to a belt and have at some rats, anything to get my feet wet and see what the ship can and cannot do. That's why there is a picture of the Dominix on this post, but more about that later. Know your ship and the weapons it carries.
3. SITUATIONAL AWARENESS
Perhaps the most important one of all in Eve. What is going on? Rushing into a situation in a ship you are not familiar with is certain o get you killed if you are not aware of the situation you are getting yourself into. Where are you? In low-sec, in Zero? On a gate, in a belt, off a station, POS tower, in enemy territory, in friendly territory, is help nearby, or not? What is the tactical surroundings? These are important questions that do not always have answers, sometimes you'll go into a fight knowing some things more than others. That's just the way it is. But the more you know, the more aware you are, the more likely you will survive and prevail.
Yesterday I broke ALL three rules.
Yep. All this talk lately about getting better and feeling like I finally had a good grip on the game of Eve? Well yesterday that harsh Mistress smacked me down and taught me yet another hard lesson. Follow your OWN rules fool.
Time? Nope, I had five minutes before I had to quit the game.
Weapon? Nope. I was flying a Dominix, which I have never flown before and it was Spider-tank fitted, which is something I have never flown before in a Battleship.
Situation? No idea. I came on and Angor said he had a Myrm in a belt, did I want to help him kill it?
My answer should have been, "No thanks, I don't have time and I don't know my ship." instead I warped into a situation that was guaranteed to kill me. And it did. I knew it would as soon as I landed. That Myrm was bait (duh, if I'd have taken a deep breath I would have known that) and his buddies showed up immediately (duh, if I would have had an awareness of the situation I woulda known that) and my Dominix was not the ship to bring to that fight anyway (duh, I knew that I just didn't listen to all those red flags jumping up and down in my head).
It's no big deal. That Dominix fit only cost me about 300m isk (because I fitted it way down in Zero), I had just flown it 17 jumps thru Zero space solo and then another 27 jumps thru low-sec without incident! lol. That's all.
It happens to all of us. Yesterday it was my turn. I hate being an idiot, but I love playing this game. So it'll probably happen again, I only hope the gap between incidents continues to be longer and longer. I think that is all I can reasonably hope for. Cause I'm not stopping.