GO BALLS DEEP. Fiddlesticks has the ability to dive turrets, pick off any squishes and incredible make comebacks.

Pros
-Fiddle goes where he pleases
-counter jungler
-fast cooldowns
-Tons of gold in the jungle
-Q-E-W combo can save him
-fear when running away
-drain has crazy range
-full build in 32-36 mins
-EVERYTHING
Cons
-really squishy
-Pre 6 is harder to gank lanes
-knock ups, taunts, silences take out fiddle easily
-NEW FEAR

Every game rush to other teams red buff with the team. (fiddle doesn't need to start a blue buff) he has 3 mana pots. Use them later on in the game.

If it fails(other jungler starts red) then start at blue to be safe.

Normal jungle route
Start at red buff(you can smite since cd is low now)-> blue buff(smite) -> widgit (or) red buff(it's normally gone and left with a little creep which is perfect for jungle times) -> golems(smite) - Wraiths -> GANK A LANE (in lane) -> Golems -> wraiths(smite) -> gank again level up to 6 -> recall (with at least 1500g)

When you get the spirit of spectral wraiths watch the gold and keep on killing big monsters to maximize item. (Average 35-40min game you get bonus 1000g+)

Q(TERRIFY) -> E(Dark Wind) -> W(Drain)
or if they might get away save dark wind and use it last
^using dark wind depends of the situation... if theres 1-2 creeps use it second but if theres more its pointless since the e will just hit the enemy champion once

Ult Q-E-W (90% of the time they will be dead)
if not fear again since the cool downs are low.

Teamwork is what is best. It's fine to get assists and not every kill. Counter jungling fiddle rely on his teammates to get out of lane in case he is caught(other team wards buffs)
Fiddlesticks is one of the best team fight champions because of his AOE ult, fear and silence.
Feed lanes that are winning let them face roll the enemy's.

In most ranked games I get tons of assist compared to kills. This is because it better to share the kills rather than putting all the eggs in one basket and most of the time enemy teams dive to kill you. Have timers or write out the time in chat so you know when everything spawns.