Thresh: I know there's already been written abit about him, but I'm missing some things.
Go Relics shield (face of the mountain). Don't go coin, even tho he's ranged, his E passive will make executing minnions easy, stats to Face of the mountain are way better for the bruiser-support role you're filling.
Laning phase Start E, for the passive-harras (don't forget, you're ranged)
If you trade, use your lantern on your adc, it's a small shield, but can make you win trades.
If you recieve a gank, You might want to lantern them in. Also flash + e is more effective than flash + q due to the hitbox, the possibility to hit 2 at once, and the added slow which allows an easier Q and your jungler to catch up
Y U NO ROAM? Thresh is one of the strongest roaming supports and can easily secure a kill, or force a back for your midlaner. If thresh has completed his mobiboots he can easily run from bottom to mid and land his skills because he's fast like that. But please, don't leave your ADC alone in lane when he's already behind.
Teamfights Help your ADC kite- Always look at your ADC's position when fighting. When they engage on you and get to your backline, flay them away and use the box, when you engage on them, and the adc is in a safe spot, flay them to you and follow up with box. (This is obvious for most people but I keep seeing people doing this wrong)
Hook: Hook dislocates a person, allowing a yasuo ult. Hook is pretty self-explanitory. (You can re-activate it to jump to the hooked champion Kappa)
Lantern: Lantern gives vision, saves your foolish teammates as well as drag them into the fight when you engage. Lee, kat, jax can jump towards it, also the summonerspell Teleport can be used on the lantern.
Try throwing your lantern on top, or a little bit in front of your out-of-positioned teammate.
Flay A god-like ability, also dislocates for yasuo ult. Great cc because it's both a knockback and a slow (which allows engage and disengage) Flay can also interupt a lot of gap closers when timed well (ex: Vi Q, Leona E, and many many more), use this to your advantage!
Extra: Don't go HAM for that single soul, but please, do collect as many as you can. As for every role- activating items wins teamfights. Please adapt your build to the opponents, mikael's saves your sloppy ADC so many times.
Little (not recommended) visual glitch; If you use your hook at the same time with your lantern or flay, it looks like it travels at a decievingly higher speed, travelspeed is the same as a regular hook still.
If people actually read this, thanks for reading! (Not a native English speaker.)