Now this is a broad question. It all comes down to what you really want from the game.
When I started I set a goal: I want a high win ratio first, and a high k/d ratio second. These are the main objectives.
I want to win the game, but I also want to destroy a lot of ships, and keep a good ratio without dying. This goes hand in hand with why dying is not good as I will explain.
You can set different goals, you can play for dsr and try to never die, or play for objectives and helping the team only for wins. I suggest your primary goal should always be to win the game (take a risk if you have a good chance of helping, not bothering for your dsr, which is second), while a healthy dsr and little deaths is a good thing too, so don’t just go sacrificing yourself in blind hope. I will explain why.
Now, whether to die or not to die. I say the game teaches you wrong.
A destroyed ship is a useless ship. Even if you are a quarter hull and survive, you are still helping more than being dead and stuck on respawn timer, away from objective. This is how almost every pug game starts going wrong: as soon as we start losing ships and presence on the main front, we are getting weaker and enemy starts pushing in. The more the ships you lose in a short time, the bigger the advantage grows. And once the advantage is over 2 ships lost or more on one side, the battle is pretty much decided. Because it just not at that moment that you have lesser numbers, but over the course of the entire remaining game (in 90% of cases), the team will be spread out due to different respawn timers, and you will be constantly outnumbered , because people don’t know how to regroup.
Ergo, the saying: “those idiots are just going in 1 by 1”. “This was an easy game. They were just coming in 1 by 1, like lemmings”. It is because they started losing at their first push, and we thinned them out, after that their respawns have set them apart, being constantly outnumbered and never regrouping against our evolving Hydra group, which you cannot kill, because if you cut one of us off, we still have full force and will replenish quickly, while you are still being at a disadvantage. So even if you sacrifice yourself in that case for… whatever it might be, it does NOT help.
So DON’T die. As long as you don’t die, it is much faster to get healed up, or just get healed up a little, your modules will get ready and you can help deny enemy push by suppressive fire and active module counter. Also, regroup. Power is in numbers.
As long as you are there, you are still helping. Take controled risks. Whenever you start taking damage, check your attacker, see if you can deal with him, if not, pull back to your team and geat healed up. If he follows you trough the lines, your team will probably take him down. Whenever you have 2 or more lock-ons, evade and pull back immidately.
Sacrificing is not worth, except in two situations:
if you carry the emp bomb and you have a good chance of making the plant
if 4+ enemy ships are chasing you through the map, while the rest of your team captures a beacon in realistic, you made a very nice distraction - even if you lost your 1 life ship, you got your team a beacon. Can also work in other game modes as well, sometimes.