This is just a build I tried with an AP/AS Twisted Fate. I thought it went very well and it gave me burst like AP Twisted Fate, but the AS of a carry Twisted Fate. I played him very much like a normal AP caster mid lane. I do not have much to save as far as a guide, but this is a build that I found to be interesting to use. I am sure others have tried something similar in the lines of Hybrid Twisted Fate. Oh, and this is my first ever post as far as a build/guide, so take it easy on me. :D I will say here that I do not have an extensive guide to Twisted Fate. I wanted to post this BUILD so that if people wanted to try this build. I know it will not be your amazing guide like how people put so much time and effort into their GUIDES. Mine is more for the stuff in the top over the stuff in the bottom.

I chose these runes: Magic Penetration Marks, Flat Armor Seals, Flat Cooldown Glyphs, and Flat Health Quintessences Because this gives him some early game bulk and near spammability of his spells to harass mid-lane. The runes can be changed as desired such as using AP per level Glyphs for a bigger punch from his abilities or Flat Armor Seals for a more durable champion against mid-lanes like Miss Fortune. These are all based on your preference of a mid lane AP-Caster.

I go with a 21/0/9 because AP Twisted Fate is the only way to play him. But straight AP will only give him use of two of his abilities. Therefore with Items he gets that extra AS. Like I said, this is AP Twisted Fate with an AS punch. SO these masteries are your basic AP Caster masteries.

My items shown above give Twisted Fate an overall decent burst with a consistent damage output. Mercury Treads or the boots I get because they give Twisted Fate a chance against these AP casters mid-lane. They also let him get out of most sticky situations when he is slowed or stunned in some way. Next, Rageblade is a must have for Hybrid Twisted Fate in my opinion. The AS with the AP and AD bonuses are perfect for enhancing any AS hybrid champion. I also have malady for the on-hit bonus and the boosts in AS and AP. The end luxury Item I decided to add for an overall dominant hybrid Twisted Fate is Bloodthirster. This gives him a giant boost in AD to compliment his AP and AS as well as gives him the lifesteal to give him those extra few attacks. It is not a sustainability like that of a full build Xin/Warwick but it will be enough to keep you in the game if it goes that far. Again, you can substitute items in like Nashor's Tooth or Hextech Gunblade as you like. Every game has its own unique build. So do not take this as a set in stone set of items. But these do seem to work well with this general Hybrid TF build.

The reason I chose this skill sequence is because it gives you big burst for early game but keeps you noticable mid to late game with that Stacked Deck. I start with Pick a Card because it gives you lane sustain with his blue card and also CC with the other two. This will help if the other team decides to invade your jungle. Along with the cooldown from your runes and masteries, the team will constantly receive some sort of CC from your cards. Then by level 3 I have one point in each skill. The Stacked Deck will help you with building up you Creep Score. After level 3 you begin to max your Wild Cards ability as soon as you can. Once you have this with all 5 points with your AP, this will give you huge bursts against most mid lane champions. It will keep them defensive and lacking creep score. After that begin on your way to maxing Stacked Deck. This is because by this point you should have rageblade built and it will help you towards utilizing your Ability. I do not max Pick a Card because I use it mainly for the CC of Gold Card and Red Card, therefore I keep it at level one for a cheaper CC. When you acheive level 18 though, it will pack quite a punch.

The Summoner Spells I choose are your basic, Mid-lane set of spells. the Flash gives you the escaping ability while Ignite gives you that extra little bit of damage to give you the edge. On occasions Flash can be useful in giving you a quick blink into the opponent along with a gold card that can give you a bunch of free damage. By the time that the opponent has come out of you stun, they will be more likely to retreat than to come at you. Just be careful because I repeat, with this build, Twisted Fate is EXTREMELY squishy early-mid game.

Pros to a Hybrid Twisted Fate:
-He remains a constant threat damage-wise throughout the entire game. He does not fall off late game like an AP Twisted Fate, but has the early game that an AD twisted Fate normally lacks.
-Makes it so that all his abilities are useful in some way
-Fun and interesting to play in my opinion.
-He is a Hybrid that actually has a place on the map
-when you are waiting for cooldowns, you can auto-attack and do significant damage.

Cons to a Hybrid Twisted Fate:
-He is extremely squishy such as he usually is.
-Slightly less AP than a normal AP Twisted Fate
-Many people do not see Twisted Fate as a Hybrid so they tend to complain about it.

All in all, I would say give it a try, if it does not work, then I apologize. If it does work, then I am glad I was able to assist you in finding a workable build. He is not your average Twisted Fate, and I do not recommend this to someone that does not know his mechanics. You definitely need to know how he is played.
Also remember, League of Legends is a team game that requires you utmost to beat the others. It requires the utilization of every ability and resource in the game. Using this and then playing aggressively and turning back here to say this was a terrible build is something I hope no one does. I really would like people to remember that Twisted Fate is EXTREMELY SQUISHY!!! He is not a tank. his base armor at level 1 without runes or masteries is 14. DO NOT go in aggressive and wonder why this build does not work for you. If you play smart and show some skill, this build will make things work when you use Twisted Fate.
Give this build a chance and if you change anything that seemed to work better, let me know. I would enjoy to make a hybrid Twisted Fate that works well and can be taken advantage of in the game.
I hope you enjoy this build and give me constructive criticism if any. This is in fact the first build I have ever done because I wanted to get my build out there to see what others thought about it. who knows, maybe it is what Twisted Fate needs to come back, or maybe this is a disgrace to the champion. I really do not know. I just know that this worked for me and I want it to work for others as well. Happy playing!