Your Flash is your distant cousin's best-friend in an odd way. You don't want to use it at every opportunity and definitely not for a chase-kill. Use it only when you are endanger for evasion.

Ignite should be used at your discretion... Either for killing a runaway opponent or as a scary poke to keep the enemies at bay. I definitely know if he/she is at moderate health I'd want to use the ignite rather prematurely to force my enemy to recall. Doing so, would allow me to take the bottom tower (whenever possible).

Always throw down your trinket ward in the middle area adjacent to the dragon. That way you can find out if/when the enemy JG is going to attempt to gank you. Many Bot ADC/APC'S despise their Support from taking their creeper count, but for every 6-10 they kill you should take one kill of minions. Even if you take an additional it should not affect the leveling system as much. As an Off-Tank you should try and get fed as much, but not as frequently as the ADC/APC. The more souls you take the better so you can become a better-early tank for premature mid game. Always initiate the attack (if possible)... Use that Q from the bushes or from a fast-paced movement to drag. If things seem like the player has a higher movement bonus and you are confident in your ally that you will not die; do not hesitate to hit Q one more time to go into melee range.

If your ally is endanger always attempt to gain distance from your ally and throw down your W so he/she may catch onto the lantern and be much further from their attacker. If/When your your opponents catch up to you and your fatally wounded ADC/APC Partner use E to close some of the gap for a few seconds. If things are going well throw down the W for a shield and walk past the radical to gain an additional shield.

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1590396703/210722947

2nd Game:
http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1590398271/210722947