Hi, I'm Lol killer 007 and I have more than thousands Ranked Game on Talon. My Rank has now reset again and I am going to give you some tips for Talon Main.
Before you want to become Talon Main, Note that you will have to use combos. So watch this video first.
https://www.youtube.com/watch?v=ow-Tx7nBfwA

Runes
Summoner Spells
Abilities
.
Item Build
Combos
Gameplay
Roaming

Electrocute - 3 attacks in 3 seconds. Use W( Hit enemy 2 times )+Q+AA, best rune for Talon
Sudden Impact - Procs your ranged q, e, and r so you can keep it basically at 100% uptime in every fight. Free 10 lethality.
Eyeball Collection - Extra damage eyeball collection.
Ghost poro - Gain ward and additional damage.
Relentless Hunter - Talon is the fast assassin, so Talon need speed to catch up the enemy
Triumph - Additional gold and fill your hp when takes down enemy
Coup De Grace - More damage when enemy low Hp, especially when you use Combos.
Absolute Focus - More damage to kill people when Talon high Hp
Nimbus Cloak - More ms in ult to catch enemies that run from your combo.

Flash - Always this, no need to ask.
Ignite - Use a combo and ignite... Free kill.

Blade's End - Talon's abilities wound champions and epic monsters for a short duration, stacking up to three times. When Talon basic attacks a fully wounded target, they bleed for 60 - 160 (+2.0 per bonus attack damage) physical damage over 2 seconds.
Noxian Diplomacy - Talon leaps to a target, dealing 60 / 85 / 110 / 135 / 160 +1.0 bonus attack damage. If cast within melee range, Talon does not leap but instead critically strikes his target for 150%. Whenever Noxian Diplomacy kills a unit, Talon restores 17 +3/lvl health and refunds 50% of its cooldown
Rake - Talon sends out a volley of daggers in a cone that return after a short delay. The initial hit deals 50 / 60 / 70 / 80 / 90 (+0.4 per bonus attack damage). The return hit deals 60 / 90 / 120 / 150 / 180 (+0.7 per bonus attack damage), and slows for 40 / 45 / 50 / 55 / 60%.
Assasin's Path - Talon vaults over the nearest structure or terrain in a target direction. The vault's speed is affected by Talon's movement speed. Talon cannot vault over the same section of terrain for 160 / 135 / 110 / 85 / 60 seconds..
Shadow ***ualt - Talon disperses a ring of blades outwards and gains stealth for up to 2.5 seconds while gaining 40% movement speed. When Talon emerges from stealth, the blades converge on his location. Each time a blade passes through an enemy, they take 80 / 120 / 160 (+0.8 per bonus attack damage) physical damage. Each enemy can only be damaged once at the start of the ability and once at the end.

I almost always start Long sword just for the damage . Whether you choose to run Refillable Potion or Health Potion is up to you. I recommend Refillable Potion in matchups where you would take easiar matchups such as Viktor.

I always buy Tiamat as the first item because you can CS minions easily. If you don't have enough gold, buy long swords as much as you can because Talon's most of the items need the Long sword.
Usually I buy Serrated Dirk for the next one and follow by Caulfield's Warhammer.

Boots of Mobility - When you want to gank the to other lanes, you need MS.
Ninja Tinba - When you face AD Champions eg. Zed, then you need Armor.
Mercury Trend - When you face AP Champions eg. Orianna, then you need Magic Resist.

If you are winning the lane and want to gank the other lanes, I recommend buying Youmuu's Ghostblade first, because this item gives you MS. If you think you can not one-shot enemies, you can buy Duskblade of Draktharr first. I run Black Cleaver because it gives Hp, CDR and Damage.

For Talon's Armor, you need an armor that gives you Damage and Armor. Guardian Angel is the only choice for Talon. It is also reviving Talon.
For Talon's Magic Resist, you need Magic Resist and Damage. Maw of Malmortius is the only choice for Talon. It gives you a shield when low Hp.

1 W + Q + AA
2 Q + W + AA
3 R + Q + AA
4 W + Q + R + AA ( Fast Combo )
5 W + R + Q + AA ( Catching Combo )
6 W + R + AA + Q ( Full Damage Combo )
7 E + Any Combos
8 Flash + W + Q + R ( Advanced Combo )

Lv 1 - Lv 3
I usually start with Rake, but if I face the assassin like Akali, I will max Noxian Diplomacy first. At first, you just farm first until Lv 3. From Lv 3, you will play more engaging but make sure you put a ward in the bush. If an enemy ganks your lane, you can use Assasin Path escape.

After Lv 6
If you are winning the lane, you will have to gank another lane. If you are losing the lane, wait for your JUNGLE gank your lane and kill enemy mid.

This depends on you, as long you have Assassin Path, it is easy to roaming and ganks other lanes.

Thank you for reading my guide.
I hope this guide will help you to become a Talon main.
See you!
( I will do a Shen guide as soon as possible )