Hi, I consider myself a main Fiddlesticks player (mostly top, but can be mid, or support - I feel like Fiddlesticks jungle is not really reliable anymore). Play Video I started on a Bronze 5 account (probably lowest MMR I have ever seen), winning 10 out of 10 placement matches and being thrown in bronze 5. Climbed my way up to gold playing only fiddlesticks (and some Urgot+Teemo when fiddle was banned by enemies or even teammates who did not think Fiddle is a suitable top). Top Lane Fiddlesticks is versatile, the build can change, the skill order can change, only runes remain the same.

For items you go mostly glasscanon full CDR (40%) with Zhonya, Morello and Banshee. Rest of the items are situational, depending on the enemy team.

The skill sequence is also situational, depending on your lane enemy. Most of the time I go 2 points in W, 2 points in E, 1 point in Q and 1 point in R. From there, you either max your W or your E (W if melee, E if Ranged or Squishie melee assassin).

I always go Flash + Ignite for Spells, this is your bread and butter for landing your Ultimate and securing the kill.

Ranked play for Fiddle top lane is pretty fun starting in Lobby. Never show your champion to your teammates because more than half the time Fiddle will get banned by them, thinking you will troll. Enemies have no clue they are fighting a fiddle top and go for the armor build, making it an easy lane for you.

Cons:
Fiddlesticks transform in late game from a lane bully to a second support, falling behind in damage and focusing on the back line with ult + zhonya, allowing your team to collapse.

Mana hungry, since your combos can eat up a lot of mana, you must preserve mana for a full combo (will look bad if you Ult and you have no mana for Q).

If not mastered, Fiddlesticks can make you look Bronze 5 on your fail ults. Make sure you hit the target and make sure you hit the zhonya in time :)

Pros:
Early and mid damage are impossible to counter. Your enemy will spend most time behind the turret trying to hit one cs with abilities.

The team fights are where you get your applauds or reports. A good ultimate in enemy back line can turn the tides of a battle, steal a baron/dragon, zone enemies from turrets.

Terrify duration will save your carries every single time and with max CDR, this will become your full-time job if you escape alive after your ultimate.

The level 2 damage (W+3x E + Thunderlords + Ignite) can bring an enemy from Full HP to Zero HP in 1.5 seconds (depending on how close he is to minions).

Always get swippers, control wards, make sure you are invisible before you Ult. Getting stunned while channeling or landing in an empty spot will make you look silly.

Your job is to disrupt the backline (NOT ASSASSINATE ANYONE, that's your carry's job), run back and protect your carry with terrify and silence. If you understand your role, you will not die and you will win more games. Suicidal fiddlesticks often make the team lose the game. Never try to 1v3/1v2, just stay with your team, hidden in a bush and wait for them to engage, then counter-attack and disrupt their team.

Since you are a lane bully, your last hitting must be good so you can zone your opponent and keep safe from ganks. That's pretty hard to do as Fiddlesticks since he has low base AD and the animation is pretty odd. You will get it eventually. When laning phase is over, just use your E to farm.

It's not easy to master Fiddlesticks, you need some fast fingers to R + Flash + Q + W + E + Ignite, that's why I used target dummies in Training Mode to make this as fast as possible. You will fail at first, but once you get the idea, the only problems will be those champions who dash away from you.
I never played Fiddlesticks Top out of Gold, but I'm pretty sure a good Fiddle player can play him in Platinum and Diamond also.
I hope you enjoyed my (first ever) guide and hopefully, I helped some of you understand the basics of Fiddlesticks Top lane.