Always be sure to keep two lanes pushed and steal farms
You're backline, and your turrets last long enough that you can keep multiple lanes pushed without even being there
Get yourself set up, and wait for any opportunity to split push
Always place your sentries apart and in weird spots, you use them for the debuffs, not the damage, since THEY WON'T STOP NERFING THAT SECOND PART
If you see a teamfight, chuck your heal in the middle of it all and plop your turrets around while looking for a reason to Rescue Beam
You capitalize on enemies overextending and punish them hard for going in
Your teammates will immediately recognize your zone as a safe area, so make sure the place is always up and running
Don't be scared to solo objectives, but only make yourself known when you've got all your abilities ready to go
Otherwise, drop your sentries in camps to quickly farm them
Identify when two turrets is enough to clear a camp and just drop them there to steal it from your enemies
You are a viable candidate for claiming level 3 camps with your ultimate, so don't shy away from that.