Hi summoners! This is my first guide! so let's take a look at Troll Builds that work #1. Enjoy! :)

standard rune page for Renekton :)

Fresh Blood over Feast for better trades or Feast over Fresh Blood for better lane sustain.
Fresh Blood has 6 seconds cooldown
Feast has 30 second cooldown when killing a unit.

You can have Feast and Warlord's Bloodlust for greater sustain or;
Fresh Blood and Fervor of Battle for greater trading.

You can also combine Fresh Blood and Warlord's Bloodlust or vice versa with Feast and Fervor of Battle

Doran's Blade and a Health Potion + Stealth Wardofcourse!

First preffed back item should be Zeal or Tiamat.
Zeal for ganking mid or responding to jungler
Tiamat for wave clearing if you just want to sit in your lane.

Statikk Shiv and Ravenous Hydra gives you faster wave clear.
Statikk gives crit and movement speed. Try to take advantage to gank mid or steal buffs from enemy jungle (don't forget to shove out your lane)

Ravenous Hydra for sustain and farming the jungle in top when the enemy freezes first or the enemy jungler is always camping topside.

Trinity Force for stronger W damage.

Ninja Tabi if your opponent in lane is relying on physical damage like Riven.
(or other Boots item, depends always on your opponent type)

Infinity Edge for bursting enemy team's ADC and AP. use Renektons E,W,AA,Q,E combo.

Phantom Dancer gives you Movement speed (5%) and 30% Crit and 45 Attack speed.

Note: if you get to item lock you'll have
80% Critical chance
+15% Movement speed
+120% Attack Speed

that is enough to burst down an Ashe, Ezreal, Miss Fortune, Varus, Caitlyn if you catch them with E,W,AA,Q,E combo.

Max Q Cull the Meek always, it will help you clear faster, Maxing E Slice and Dice next is very efficient for AD heavy compositions. Q Ruthless Predator does not scale per level, it scales with your AD (+.75/AD) so you want to max this last because later in the game you'll have higher AD all in all.

Use your Ultimate Dominus Early on all in so you will have better and faster DPS

Flash and Ignite for higher kill threat
Flash and Teleport for ganks and responding and returning to lane faster.
Flash and Ghost for keeping up with squishies or going all in with an opponent with many cc like Riven, Nautilus and Maokai

Renekton wave clear is fast so be sure to ward in your bush or tri bush (depends if you on blue or red side top lane) when you tilted your top lane opponent expect a collapse/gank from their mid and jungler (as what low elo players do) or if their too dumb to respond to their top laner continue snow balling your lane until you have destroyed the Inhibitor (My expirience so far)