General rules of thumbs to make team like you:
Stay with your team. It’s OK to lead, but make sure you can reach them quickly or provide range support at least.
Always hold medkit and patch your teammate
Don’t do friendly fire, especially when using javalins, unless you want to save your teammate from special or elite. If you hit someone, say sorry. Most random players are nice.
Watch teammates’ back. If a teammate can handle a few elites and mobs, I would let the teammate deal with it and turn to other unguarded sides.
Tag resource and tell your teammate who may need it.
I wouldn’t actively go for the kills in the scoreboard. Besides, SotT don’t need to farm THP from kills. If someone screw up and all my teammates falls, I will have the chance to carry the game. Most people don’t care about the scoreboard. But if you can save a game, most people will say wp at least.
If you want books, better say it in the beginning.
Bleeding thorn can prevent your teammate from being overwhelmed, except cata. I would save one ult at least for emergency.