Overwatch draws heavily from arena shooters, coming from a background of Quake III, Unreal Tournament and AssaultCube, I slid right into the metagame. Most people who pick up OW tend to be from Call of Duty, Rainbow 6: Siege, Counter-Strike and sometimes from Paladins. The thinking involved could not be any more dissimilar. Here are a few things you should stop doing right away.
GENERAL MAP AWARENESS
This isn't something that happens in a day. Generally speaking, OW maps have three lines — the direct path through the middle, which is the widest, and two narrow flanking corridors. Regardless of your payload position or objective, you will always have three different ways to approach your quarry. As a pure DPS carry like McCree or Soldier 76, you should be using the flanking lanes to get the opponent from behind or the sides. Your tank should always keep the opposition engaged through the most direct route down the middle, opening up space for the DPS players. As for supports, know where to hide and when to come out. Assess each death and correlate it with your position.
NOT PROTECTING THE SUPPORTS
Your Mercy, Lucio or Ana keeps your team ticking. A support can make or break a teamfight with their burst heals or resurrections. If a Genji has been repeatedly killing your Mercy, instead of being the Pharah that types "noob support" in all chat, you should be looking to pick out Genji. You don't have to constantly escort your support, all you have to do is make sure your support's counters are shut down.
EXPECTING THINGS TO GO FINE WHEN YOU PLAY DPS DURING SOLO QUEUES
Oh boy, I never play Overwatch without a three-stack. In solo queues, everyone first picks Genji, Hanzo, McCree quickly followed by a tank (if you're lucky) and/or a defence hero like Junkrat. This leaves the final person to either pick support or Tracer because kills are everything, wins aren't. It's natural to rage when things don't go your way due to the team composition. Rather than constantly blaming the people you queue up with, find or make friends who will queue with you and rotate duties so everyone enjoys the game.
LOSING TRACK OF THE OBJECTIVE
You rarely get moments when there's nothing to do in OW. Sometimes after a teamwipe in defence, you might be in that position. Unfortunately, a lot of DPS and tank players feel that it's their duty to go hunt the opponents at their base. This usually ends badly and you lose the objective. Always get your priorities straight.
Are you playing support? In that case, focus on your tank but don't forget your DPSs. A tank can take a lot of hits at 20 percent health but a DPS is one shot away from death at 20 percent. In these scenarios, quickly heal up the DPS and go back to the tank. Also, as Mercy, don't left-click and forget. When your DPS is dishing damage, right-click them to boost the damage. This also goes for tanks. As long as they have at least 70 percent health, you can damage boost them unless there's heavy burst fire on the tank. A boosted tank is as good as a DPS. For Lucio, your speed boost can be great in teamfights to dodge enemy attacks for the entire team.
DON'T PICK WIDOWMAKER
Unless you're GM or Diamond with Widowmaker, uninstall the game.