Focus on dodging Wild Cards early when your champion doesn't have the hit point to afford getting hit.
If you have low Health, use Destiny as an indicator to run to safety. It will give you a head start in escaping any possible ganks.
Due to Wild Cards having one of the highest non-global non-ultimate range in-game, he can harass very well. This makes him a good pick for mid lane. While the projectiles are slow moving, the long range of the cards often catch enemies by surprise. Additionally, the projectiles, unlike many skillshots and pokes, will pass through minions, and even do damage as multiple targets are passed. This disallows opponents from blocking with their waves.
Use this to gank other lanes with Destiny, as your minions will be pushed up to ensure your turret will be safe until you walk back to it.
You may also attempt to Red Card a minion nearby an enemy champion to slow the champion and set yourself up for harassing them with Wild Cards.
Pick a Card has multiple utilities. Blue Card can help Twisted Fate stay in lane longer as he regains mana back more quickly. Gold Card is very useful when chasing down an enemy or when ganking since it stuns the enemy it hits. Red Card can help Twisted Fate push, farm, gank, or chase down an enemy because it deals splash damage and slows the targets hit. The area of effect of Red Card may also be a more useful effect for peeling allies and kiting enemies than Gold Card if it can hit multiple targets, especially when teams are fighting in the tight spaces of the jungle or at lower levels when the duration of Gold Card will be much lower than the duration of Red Card
The three different cards in Pick a Card are in a set rotation. Blue Card, then Red Card, then Gold Card, and it repeats; the starting card may differ each time you use Pick a Card, but it will always follow that rotation. This rotation is very important to allow you to predict the time it will take for you to lock in a card and throw it.
Twisted Fate is relatively fragile (squishy) so make sure you keep your distance. Twisted Fate is capable of repeatedly stunning one opponent (with Gold Card) or slowing multiple opponents (with Red Card) every few seconds, even more often with cooldown reduction. Abuse this while chasing, ganking and escaping pursuers.
The abilities of Twisted Fate may have low cooldowns, but an ability power-focused Twisted Fate is nonetheless highly vulnerable while his abilities cooldown. Avoid committed fights against enemies with a current health count that you can't easily burst down with Pick a Card and Wild Cards, as AP Twisted Fate will almost certainly lose to them.
Destiny and Gate can be used to quickly backdoor enemy structures. Used in conjunction with another great backdoor ability, Pick a Card, as the bonus damage is applied to turrets, it's pretty difficult for enemies to defend.
Picking Stacked Deck as your first ability can lead to a large amount of single target damage, combined with attack speed runes, it is a very good way to get first blood. However, Gold Card helps greatly, and so waiting until you are level 2 can give you better chances of a kill.
Map awareness is key to proper use of Destiny. Look around the map carefully while farming or traveling for potential foes.
Be sure to ping onto targets just in case your allies don't have the same map awareness as you do when you plan to use it! Twisted Fate using Gate against a sole target is unlikely to work well while the cooldown of Destiny is fairly long for a lot of the game.
When a team fight occurred and you already cast the Destiny at wrong timing, position or your team mates eliminated, it can be interrupted using Zhonya's Hourglass.
It is generally a good plan to have a card already chosen by Pick a Card before using Destiny, especially if you're going to land close to your enemy. You should lock onto Gold Card and then activate Destiny and its secondary effect, Gate, to gank an enemy. You can also use Pick a Card while channeling Gate, allowing for a faster Gate due to not having to spend time locking onto Gold Card.
Make sure not to use Pick a Card too early either, as having your Gold Card run out as you Gate will lead to embarrassment and likely a fruitless death.
Keep in mind that Destiny will pop your enemy's Banshee's Veil but this will also prevent him/her from being revealed by your ultimate (you can still use Gate though). Meaning that against a team with multiple Veils, you can use Destiny to pop their shields before a big teamfight. Be warned that fleeing low-health enemies will likely be guarded by their allies that remain invisible to your ultimate (and you will only know it after teleporting to kill them and be ganked yourself). Coordinate with your allies for the best time to use Destiny to ambush enemies.
In a pinch, try to either juke your enemy and then run into a bush, or stun them with Gold Card. If successful, pop your ultimate and start teleporting away with Gate. By the time the enemy has a chance to attack you again, you should be a safe distance away. This technique can even work out in the open without Gold Card if you wait for the enemy to pop all their crowd control first.
Twisted Fate's primary combo to harass is to activate Gold Card with full Stacked Deck stacks, walk into attack range and stun the enemy, then follow it up with Wild Cards and walk away while the enemy tries to dodge the attack. Twisted Fate can then use Blue Card to last hit while regenerating mana and do the combo all over again. This combo is not foolproof because enemies will realize when Twisted Fate activates Pick a Card and be prepared to fall back, or even use Twisted Fate's short autoattack-range for applying the effects of Pick a Card to easily predict where he will have to walk to use it to set up skillshots.
Stacked Deck gains a stack for each autoattack and deals extra damage on the fourth hit, but Pick a Card will vary this depending on the scenario.
If using an ability power build, Lich Bane is a great choice due to the ability power ratios of Twisted Fate being fairly low and will not cause very much burst damage on their own later in the game. Additionally, the conjunction with Pick a Card ensures in large damage with one attack.
Rabadon's Deathcap is mandatory for Twisted Fate, as with all AP mid laners. However, the passive makes it more viable as a second or third item, when other items have been purchased and some AP have been amassed.
Twisted Fate is relatively fragile at early game, putting an aggressive pressure on the lane can make him under-leveled or under-farmed.
Twisted Fate has fairly poor sustained damage with an AP build - if you can get movement-affecting crowd control on him before he stuns you as a champion with a greater sustained damage potential, you may be able to turn the trade in your favor.
While Wild Cards has a nearly unmatched range that makes stopping Twisted Fate from farming while he has mana to cast it impossible, you can harass him when he uses Blue Card as it's limited to the range of his basic attacks.
The Wild Cards can be tricky to dodge as it travels in 3 lines and moves a long distance. Instead of going back, try to sidestep the spell.
When you are under the effect of Destiny, be prepared for a gank as his Gate allows him to teleport a huge range across the map.
Gate has a noticeable channeling with a marked location, and this can leave him an easy target for skillshots. If the skillshots apply crowd control, this can stop Twisted Fate from getting you killed or maybe even turn the gank onto him!
Dashes and blinks, if saved, may allow you to avoid Gold Card if used while Twisted Fate is teleporting to a location on top of you.