Try to complete the objective of the matches. Kills matter, but in Tower Control and Rainmaker, they are best when clearing paths.I hit level 10 today. Which means Ranked Battles just unlocked. Do you level up faster in those?
Anyway, just to avoid being that squid/kid, what are the dos and especially don'ts of each mode? Weapons to bring, strategies to use.
I imagine the Aerospray is fair enough for Splat Zones, but for Tower Control and Rainmaker, I don't know. I'd think Rainmaker would mean a weapon made to splat enemies, and Tower Control means something with decent range?
Also with those two, learn the paths to the finish for each map, Rainmaker especially, and keep those clear for your team if you aren't on the tower or in control of the Rainmaker.
Splash Zone, try to pay attention to where blasters like to camp and if your team is having trouble, go for the blaster and take him out, or at least throw a bomb up there to force them to move.
Bombs are useful, some teams like to group up and a well placed bomb can take out an enemy team. With that, try not to group up too much so the same doesn't happen to you. That doesn't mean go the opposite way, but you don't need to have three or four people on the tower when bad guys are coming in. Sometimes being a distraction cam he enough to finish out the round.