Quinn has been my baby since the start of season 5 she has been my goto if I want my laner to cry, has been my elo climber for the whole time, I am like most of the people in season 6 that went 5/5 and got in bronze, playing Quinn in this elo is amazing the blind throws them off so well (since well they are bronzies they tilt after first blood) Quinn has been and always will be my favourite champion.

First picking Quinn doesn't reveal much since she can fill 4/5 roles although Adc is weaker for her.
Quinn is a master roamer so use that power, mid isn't fed enough? -roam Adc is behind? -Roam All lanes pushed? Ehhhhhh stick with cs for that. Quinn isn't like a nasus who stays top, her ult promotes roaming and helping your team.

Teleport is taken most times, good for snowballing other lanes (better to save for botline fights.
Flash because it's good disengage and engage.
Ignite is the snowbally spell also take it vs Dr mundo and volibear because their hp regen is sad.
Ghost isn't advised since Quinn gets alot of movement speed items

Pro's:
High mobility.
One item powerspike.
Good in low elo
Easy to play.
Powerful roams/gangs.
Tp Ganks are crazy.
Fun.
The blind... Nough said.
Very hard to tower dive.
Free vision while teamfighting.
Kills armor tanks quickly
Con's:
Squishyyyyyy.
Abilities are one person lock down.
Low damage early.
You have to play with alot of respect for your laner until ghostblade.
Homeguards get annoying after rapid-fire cannons speed (sanic speed).
Locked down easy.
Teemo... Nough said.
Need armor pen to be useful.

Quinns runes can be done in many ways.
2 armor pen Quints gets some damage for Quinn before her ghostblade.
Armor pen reds
1 attack speed quint is a good buy for most Adc champions like Quinn.

Armor seals and Mr blues are solid for early survival and early mini tank stat's that Quinn misses all game.

I'm sure most people are confused about no thunderlords, personally if your going to build Quinn assassin (ghostblade rush) fervor is better, thunderlords is better for poke champs like ziggs, deathfire is decent on quinn too I normally take it when the enemy team is extremely mobile.
Battering blows is awesome for Quinns early game, provides more armor pen before the yomuus powerspike.

For Quinns build you focus on 4 things raw ad, armor pen, attackspeed and crit last.
Yomuus ghostblade fits 3/4 of Quinns much loved stat's.

Gage is awesome on quinn since she her base damage of abilities are high, also provides that amazing sheild.

Out of the Zeal items rfc and shiv are the best for wave clear and extra damage.

Boots of Swiftness are a good buy for a roaming Quinn and also gives that extra speed for flying back to lane.

Maw/hexdrinker is good for another little shield and more armor pen, and more attack speed while the passive is active.

Last whisper lord D provides more armor pen for Quinn and gives more damage to those heavy hp tanks.

Duskblade can be used to finish the build (after selling boots) it provides the last bit of armor pen needed for Quinn, and the "zed ultimate"

Or if the enemy team is stacking hp like crazy, blade of the ruined king is advised.

Any champion that has a speed up for your team, eg Sivir ult.

Champions with a flip/ point and click stun (singed and volibear) / (Taric and Annie)

When entering a fight 1v1 or whatever) don't engage with vault, wait till they have used their gap closer (eg.Flash)

Vault cancels many champions abilities if timed well. Eg: Leblanc w, riven q,Gnar E and Katarina ultimate.

When your backline is getting dove by a bruiser/assassin vault them then blind to limit their damage.

While taking a tower hit the Harrier marks on the minions to get extra attack speed.

Quinns w is free to cast at all ranks, whenever you think you are getting ganked just use it, it's on a peanuts cooldown for what it does.

Quinn is amazing in low elo (just don't e until all the enemies cc is used)

Always look for tp Ganks in botline, but let your Adc have the kill, them snowballing is better than Quinn snowballing.