So, to start off, don't do anything, including killing Xenos, this cripples the hive, therefore leading to Marine victories. What you can do within staff favor is hang a sign around your neck that says I'm sorry, i.e.:
If you want to be a good survivor, instead of a neutral one that just gives yourself up: gather all of the wildlife you can and get them to one spot, this makes it easier for the Xenomorphs to devour them and bring them back to the hive for larger population numbers.
This is a stretch here but, make a stun-prod and try to disable the other survivors, this way, the Xenomorphs don't even have to run to catch their prey, they just lie on the ground waiting, brilliant!
If anyone has any suggestions on how to play survivor better, please, throw them in the thread here for reading. And remember, everyone: