Early game
Use your oracles to get rid of the opposing ward coverage, so that you can stun them from out of nowhere. This will lead to your ADC getting fed, and bot lane snowballing. GG.

Remember, ALWAYS use stuncard. There is no other ability TF needs. Simply use it repeatedly to set up kills and escape. Any situation, stuncard is probably the answer.

Late game
If for some reason you haven't already won from bot snowballing wildly out of control, don't worry. TF is the master backdooring. Use your smite on the siege minion to push super fast with your Q. If the opposing team comes for you, use either your ult or stuncard to get out of this sticky situation. Soon you will push your team to victory.

Ok, there are alot of masteries, so I won't explain, however I will high-light a few important masteries to have, and you can copy the rest.
Sorcery is important to max, as the cool-down reduction will help you to put out more stuncards.
Butcher and destruction are essentail as you will need the extra damage vs creeps and turrets whilst backdooring.
Meditation is key, as the extra mana regen allows you to sustain more stuncards in lane.
Lastly, improved recall is probably the most important mastery as if your ult is down whilst you are backdooring, you can make a quick get away using recall.

You want to max your W first. W is the most important ability to TF support play, purely for the stuns. As I will hilight later, always select the stuncard, as then you can set up sick kills for your ADC. All other cards are comperatively useless. You will want to get you ult leveled at 6, 11 and 16 as your ult is key for making esacapes whilst backdooring. Then you want to level your E. This will increase your damage and attack speed. Remember; more damage is better than less. Lastly, level your Q. This ability is leveled last as it isn't at all useful for early game as you dont want to steal your ADC's cs. However, it is useful late game (when you level it) as you can use it when your backdooring to push lanes uber fast.

You don't need to farm; you're a support. Just sit back, let the ADC do the work, and throw in the occasional stun card.

Main build
-Wriggles lantern
I know what your thinking; sightstone is a great item for supports. WRONG. TF only need one ward. This is because, two wards is overkill. You only need river warded. If you need any more vision, simply use your ult. Wriggles lantern is useful as it gives you sustain through lifesteal, and gives you extra damage vs creeps to help with pushing and that all important backdooring.

-Runic Bulwark
Every self-respecting support gets this item.

-Lucidity boots
TF will need this cooldown reduction, so he can put out more stuncards. Stuncards are essential for everything in twisted fate play, so more stuns = better.

-Shuelya's reverie
Want to stun someone, but they are getting away? Use this item for its active so you can get in range to use your stuncard. Also the cooldown reduction will help you to use more stuncards.

-Ohmwrecker
This is what truly makes TF op as a support. Say your opponents are scared of you, and decide to farm under the turret. Use this items active to block turret shots, so you can dive, stuncard, and set up kills for your ADC. Also it gives AP, which will help scale damage on your stuncard.

-Zeke's Herald
The lifesteal on this is essential for TF's sustain whilst in lane and backdooring. Backdooring is essential for TF play, so this item is super good. Also cooldown reduction to improve your stuncard output.

Starting items
I know what your thinking. An oracles at the start. Trust me, use the oracle to stop early ward coverage, so that you can use your stun cards to stun the ADC out of nowhere, and BOOM your ADC gets a kill. GG.

Situational items
- Statikk Shiv
In case your team is behind and losing, buy this to backdoor you enemy team. This will draw away the opponents from your team, and help get objectives. TF is great at backdooring as when the opponents come to stop you, just ult into another lane to push, or simply use a stun card.

-Bloodthirster
Need more damage? Get the bloodthrister to do more damage, and have sustain when backdooring.

-Warmogs
Dying too often? Someone on your team is a n00b-feeder? Get warmogs to help your survivability in these tricky situations.

Pros
- Backdooring wins games. You WILL carry your team to victory using this guide.
- Stuncards ARE OP. Stun your opponents in lane, and the ADC WILL get fed. Again, this will carry your team to victory.
- No-one expects the Spanish Inquisition! Seriously, most nubz in low elo won't suspect twisted fate support. This means you have the element of surprise on your hands, as well as those op gold cards.

Cons
- I'm pretty sure there isn't any cons. If you find any, please tell me. Although, you're probably not doing it right and are one of those n00b-feeders which are keeping me in bronze league.

Smite
Use smite on the siege minion when possible. This will help push lane, and give your vital backdooring the edge it needs. Also, if the opposing team is taking baron or dragon, use your ult in combo with smite to steal it and carry your team to success.

Clarity
Clarity is also vital for giving you mana sustain, when blue card simply isn't enough, so that you can carry on with that all important stun harass, that feeds the ADC.

TF support is strong against ALL bot lane match-ups. If you are at all in trouble, select stun card and use it against them. This will counter any champion.