You have a lot of early damage with this build. You want to abuse your laner with your E pushing a minion towards them to slow, then immediately start your Q on them. With this knock up it gives you time to abuse them. Trading usually ends in your favor with the massive slow on your E.

If you are countered and can't farm well consider using smite occasionally for cannon minions. Also farming under tower letting the harasser push the lane.

To be relevant with this build you must constantly be out of the lane when either 1.Your laner is not their or 2.You are pushed to their turret. When you're out of your lane you must be farming the enemy jungle camps or searching to kill the enemy jungler with or without your jungler.

Ganking with your jungler to other lanes helps other lanes excel. For instance if you are in blue team's East jungle (you are red), you can easily farm the jungle, catch out their jungler, or seek out to gank bottom. Since you get tanky early you can proxy between their first and second turrets for a wave, and then ult to the tower with your bot lane and crush their bot lane. If the jungler shows up as well that just adds to the tower dive. Personally I save my TP after the fight to go back to top in case my laner is pushing to tower.

The Skirmishers Sabre makes for good smites and adding damage to the ganks you make. This, Black Cleaver and your E-Q combo make you stick like glue to the enemy champions.

The reason you must rush the jungle item is to get you that crazy smite. The smite allows for true damage on to your target just adding damage.

Teleport is generally saved for getting back to lane when either ganking other lanes or invading the enemy jungle for jungle camps.

You want to buy wards and upgrade your trinket ASAP as you will be in the enemy jungle a lot stealing camps and killing the jungler. They are meant to keep you safe just by knowing the location of multiple enemies.