*Updated and valid in LOL since 12/01/2011 and won't change for a while.
This TF guide is IMO a very balanced build ensuring your TF stays relevant throught the game and not just in early game/mid/late game.
Note: I mastered TF to the point I win almost every game i play even with the worst teams.
This TF will carry the team to success if played properly.

- 30% attack speed from runes and Sword of the divine combine very, very well.
- You'll find the added HP regen will help you stay in lane substantially more.

Ghost and Flash helps you escape traps and embarrassing situations.
Stay Alive! (HP runes are here for the exact same purpose).

They longer you stay alive the more XP you'll get from minions and the more chances you'll have to take advantage of enemy mistakes.

When the opportunity arises use ghost and flash to catch your enemy with a gold card of course!

Notice how I only gave 4 basic items.
- These items scale your TF nicely as you buy them piece by piece.
- Sword of Divine is just made for TF!
- Vampiric scepter turns into Bloodthirster and leaves no outdated item slot when you get to late game.
- These basic items will give you an awesome start no matter who you play against.
- Late game I find:
(1) Guardian Angel is good if you're constantly targeted.
(2) Mardreds bloodrazers is good if the enemy team is HP/Tank oriented.
(3) Another Bloodthirster will turn you into a superman.

This build will show its strength only if you play it correctly:
- Always try to stay in lane until level 6. Then you can go back to base, buy some stuff and Destiny(teleport) your way on a usually weakened enemy anywhere on the map.

- Practice pulling gold cards *ONLY*.
- AP TF is out of the question for some time now since he was nerfed in a patch.
- Always use Destiny combo with a gold card ready to gank unsuspecting enemies.
(if you dont know the combo look for it in youtube).
- Don't be afraid to ask your team mates to lure enemies away from their towers for you to have enough ganking room.
- Movement is everything! Movement spells and Destiny teleportation give you the best CC in the game. people will fear you. ppl will hate you. ppl will lose just because Destiny ganking has a devastating mental effect.
- Do try and play mid lane. TF really shines with the level difference as a soloist.

Summary's summary:
This style of play is very hard to master but is also very rewarding. It takes a lot of skill and a lot of patience but winning games with difficult champions will make you feel like you-are-it!

p.s., I'm always open to suggestions.
Good luck.