It based mainly of your kill/death ratio and how high it is.
The more kills you have compared to your deaths the more skill points you gain
NOTE: The skill points awarded for this are actually a small fraction based on your current level and such, so you may recieve around 2 points for a high ratio at low levels and only 0.0001 points at very high levels
It awards them based on good you are basically, and you get a good bonus to your skill level if you are MVP for the match
My advice is to just be careful and go for the low kills and even lower deaths method. sticking to the walls and cover and using a medium range weapon to take out your enemys.
It won't give you as much points as you want. But i rather earn some points for having 5 kills and 1 death than lose some for getting 15 kills and 30 deaths
