I have recently started playing Poppy and like her play style. You can play Poppy so many different ways and I have tried many approaches: AD, AP, tank, and hybrid. Though poppy is a great tank, Valiant Fighter works better if Poppy has less health. This allows Poppy to be a carry that doesn't take a lot of damage. AP is awesome, but I had a harder time in team fights without the extra survivability. When I added survivability, I lost my burst damage. AD build is amazing, but it is boring to me and I like a challenge. For the above reasons, I have been working with a hybrid build. This build is not complete yet and I am still working on it, but it has been working in ranked games for me.

One of the main reasons I like hybrid builds is an opponent cannot just stack armor or magic resist to counter you as a carry. Poppy does both a lot of burst magic damage followed by physical damage.

The masteries I use are fairly straightforward except for a few things:
-Cripple and Burning Embers: See below for using exhaust and ignite
-Resistance and Hardiness: I found that taking some extra survival helps a lot in ranked games. It will save you some deaths and the other team will leave you alone if they see more armor and resistance. This allows you to be a good tank if your team needs it.

I am still working on runes that are best for hybrid. I personally need the extra health from Seal of Vitality because of my aggressive nature. As for the runes that increase damage, I chose armor penetration and ability power runes. I have played a few with all AP or all armor penetration and have not seen a difference. The mix allows for a boost in burst damage and normal attack damage.

I grab Doran's shield as my first item for a few reasons: I am an aggressive player and I need the extra health and armor, it allows me to stay near the minions to last hit easier, and I get to stay in my lane longer with the extra health regen.

Sheen is the Poppy's bread and butter item. This eventually will be used to make Trinity Force, which helps Poppy in every way possible except life steal.

Hextech Gunblade is the item for any hybrid build and gives Poppy the life steal she needs.

Sword of the Occult and Mejai's Soulstealer are the high-risk, high reward items of this build. They are worth it and I have not been in a game where they have not been able to stack quite a few times.

I grab a tank item to replace Doran's Shield in the end game. I personally like Banshee's Veil or any other magic resist item, since Poppy's ability give armor boost. If I am doing well and do not need a tank item, I grab Abysimal Sceptar to give some extra AP.

I grab Heroic Charge as my first skill in order for a chance at a first blood. I do not upgrade Heroic Charge again until late because it does not increase the amount of time stunned. I grab Devastating Blow to either farm or get a kill with Heroic Charge. I max out Devastating Blow first because it deals the most damage and has the lowest cooldown. I max out Paragon next to increase survivability and farming. Opponents that see a high armor will be lest likely to gank you because they think you stacked tanking masteries and runes, and the ones that do try to gank you are usually punished by Poppy anyways.

Grab Doran's Shield and head to the bushes in the river near the outside lanes.

First kill for Poppy is very easy compared to most character. I like to lane with a tank, so they can search bushes early. Heroic Charge the squishy, exhaust, ignite, hit 2 or 3 times...dead. Congrats on first blood. If they are not dumb enough to hide in the bushes then you are out of luck.

I stay in lane until level 6. I port back and grab sheen and the boots if I can.

This is the fun part of being Poppy. After I grab sheen I run between the top and bottom ganking when I can. Some tips to think about:

-Try to Heroic Charge opposing players into your turrets.
-If the have a jungler on the opposing team, take advantage and kill him, Poppy is excellent in the jungle with Heroic Charge. This advantage is high when you hit level six, because a jungler is usually behind by a level or 2.
-Do not forget to alert what opposing champion you are going to kill so your allies can help you out to make it that much easier
-When initiating, hit Devastating Blow before Heroic Charge to get the highest burst damage possible

Once you grab Phage the ganking becomes easier because you slow the opposing player.

Once you get Hextech Gunblade, Poppy seems OP. Not only do your attacks slow an opposing champion, but now you have an extra slow. Do not forget to use this on champions running from a team fight.

The late game is where the risky part of the build comes into play. Having both Sword of the Occult and Mejai's Soulstealer is risky, but is very rewarding. I usually win before I get stacks on Mejai's.

For team fights it is Poppy's job to kill their carry. Focus on any champion who has a Mejai's or Sword of Occult, in order to ruin their stacks. There is not much else to team fights other then knowing how to play Poppy.

Updates will be coming. Please comment.