I only had the luck to find a good team once, and played to end of 3 chapters, when say good, is people who stay close to each other, to revive if needed, actually use battlecry to help teamates, tag enemys even that they dont shoot them (for teammates), chose a balanced arsenal and dont rage quit after the first dificultie.
So the next time you need somebody, you can invite me if im online, if you want, of course.