AD: Attack Damage
AP: Ability Power
AS: Attack Speed
CC: Crowd Control
CDR: Cooldown Reduction
Squishy: A reference to a champion easily killed, ie low hp, armour, magic resist

Pros: Some good CC - aoe slow with red and a stun.
Great farmer using red card/wild card combos
Good lane sustenence with blue card mana regen
Able to dish out constant dps as well as burst magic damage
Global tele great for ganking and backdooring

Cons:
Squishy with a low attack range, putting him at considerable danger in team fights
Low base move speed.

Recommended

In general use flash to escape if u take some heavy burst damage, and ghost to pursue. Of course there are some exceptions, e.g you need just that little burst of distance to last hit an enemy, or to get that stun on him if you overshoot Gate.

Viable:

( Cleanse is great when used in sync with ghost for getaways, Exhaust again is not a bad option, use it on high dps champs for the damage reduction.
Ignite probably not the best as your ganking should leave enemies with no chance anyway. Heal is good for some situations, e.g tower diving or countering karthus (boy does that ult make me rage :O) but if u take continuous damgage heal just wont cut. Which is why you have flash in the first place: avoid such situations.

Never Take/ For Troll(olololol)ing

The heal/revive combo... so pro. not. Yea anyway no fortify, no revive, no tele(you kinda have a global one).

1.Q (wild cards)
2.E (stacked deck)
3.W (pick a card)

lvl Gate whenevever you can.

Q hits extremely hard early game if you lvl it-use it to farm (with red card of course) and harrass. By lvl 9 it hits 260, almost a quarter of a squishy's hp (assuming that you took mid meaning everyone else is around lvl 6-7) making it great for those early game ganks, as well as lane harass

E also has most of its potenital early game (it does stay usefull with attack speed and AP we build, but it isnt quite as usefull during late game) which is why we lvl it second. W is mainly for CC (red and gold), along with farming (red) and mana regen (blue) One lvl is enough. It simply is not worth lvling this over Q or E as the dmg output does not compare to either, and the CC increase per lvl is mediocre.

1. Dorans Sword: Increased damage ideal for last hitting as TF a low base attack, as well as granting him some survivability and hp regen.

2. berserker's greaves: standard of any pure dps carry

3. Trinity Force: A bit of everything, attack speed, AP, slows, movespeed (absolutely necessary for landing those stuns in chases), health and crit as well as the additional 150% of base damage to your w, significantly buffing its damage.

4. Hextech Gunblade: Massive damage and AP as well as lifesteal, spell vamp (it constantly procs off madreds and stacked deck) and an activatable ranged slow that works great with Gate ganks.

5. Infinity Edge The meaning of crit to a whole new lvl. crits now hit 250%, also gives 30% crit and 75 dmg.

6. Phantom Dancer Attack speed, 30% crit chance, move speed, helps pursuit/escape with a major buff to dmg. Where there is an Infinity Edge, there is a Phantom Dancer.

7. Madreds Bloodrazor: that 4% of health per hit sure does chomp up tanks (and anything else living), attack speed, dmg, a little armor. passive procs off spell vamp.

I strongly advise taking mid lane as Twisted Fate's high base-damage abilities make him a powerfull early game champion, and we want to use this advantage for easy kills through early Gate ganks. Use wild cards (Q) to harrass along with your red as you only need to hit minions near to the enemy champion. It is of vital import yo spam blues for mana regen.

Farming with TF is simple: wait for minions to bunch up and hit em with red card. Follow up with wild cards. This is more of a late game strategy where your abilities do more dmg and you have more mana to expend.

Tf's strength lies in utility to the team, able to turn teamfights by joining in at any time with Gate, and backdooring turrets similarly (refer to last chapter: backdooring).

As soon has you hit lvl 6, keep an eye out for ganks. TF's ult makes him the perfect ********er ganker*. An ideal situation would be where the enemy champions are past halfway point in their and relatively close to a friendly turret-this gives you time to kill them if indeed a pursuit takes place. When you ult, ALWAYS position yourself to be slightly in front of them, so that there is no escape. If you overshoot there is a possibilty they maybe be able to veer left or right and evade your stun. If you think you can go 2-3 shot an enemy, go ahead and ult even if it means right under their turret.

Always use yellow card for ganks, and hit the squishy. Follow up with wild cards as they are stunned, giving you a 100% hit chance (assuming you CAN hit motionless targets :P). If you arent able to burst the squishy down, pursue untill you have another gold card up. Ghost if necessary.

TF's global tele and creep wave clearing abilities makes him the best (IMO) backdoorer in LOL. The trick to this is knowing when to act. WHen the enemy team is distracted, ult to the friendly creep wave closest to an enemy turret, and take it down. If there are several mias, walk up and use ult as an escape mechanism.

Oppurtunities
Stalemates at towers:
usually the attacking team waits for an opponent to overextend from their tower to eliminate him/her, which requires a bit of concentration.

Aced Enemy Team:
During this time your team (if they have any sense) will push a tower. If there are any other creep waves close to a turret, ult to them and push that turret as well.
Aced

These are at the safest times you can bdoor with the most success: If you think you can destroy a tower even at a high risk for yourself, go ahead. A tower for your life is a bargain.