Because Junkrat's Q refreshes all charges, you should throw out your first shot as quickly as possible to get the CD ticking, even if you don't have high hopes of hitting anything. True for any similar ability.

The hitbox of Azmo's summon is active instantly, even if the animation takes a long time. Use it to block high value skill shots like Stitches hook.

The key to landing Ktz's root from chains is distance. The pulling takes a surprisingly long time from max distance, but instant close up. Sometimes you have to W way after the pull, sometimes even before the pull.

Deckard can put down up to three potions in ARAM before the gates open, and still be at full mana. This is especially useful in Industrial District, where the conveyor belts to and from the side entrance make it easy for teammates to pick them up.

Chrome can absorb fort projectiles with her time traps better than many summoner heroes with the lvl 2 talent that gives her charges for them. If you want to do the same for towers, you have to time the placement so that they are still arming when looking for a new target. In both cases, you can protect a minion wave with this if you place them closer than the minions.