Here's the deck I just used to win 80% of my games after Legend #30 . Finally got top 10 so I thought I would share. I think druid is very strong in this meta and that's why I went with it. No sense writing a guide for combo druid since everyone is familiar with it by now. Instead I will explain the finer points.
Mind Control Tech: This thing won a lot of games. When druid falls behind on board, it struggles to get it back, so swing cards like this one can save a lot of games. It greatly improves the mage and zoo matchup, which can be tricky. You can also toss this thing out on 3 as a body which is important for board presence early. This card is never bad, versus say, Zombie Chow which is worthless and infact hurts you after turn 1. More on Zombie Chow later.
Senjin: This used to be Rag but I needed a more consistent early board. When you wild growth on two, you need a 4 drop on 4. The shredders often aren't enough, so this is basically a third shredder. This and the MCT almost guarantee you get something going early on. It also helps against hunters since this list only runs a single belcher.
Your muligan is pretty consistent across every matchup: wild growth, innervate, shredder (if also have innervate), shade, and keeper. You always keep shredder or keeper with an innervate. You can keep swipe against paladin sometimes if the rest of your hand supports it. Possibly against lock, but it's bad against handlock.
Sometimes you keep wrath. Depends on the read you put on your opponent's deck (aggro/control), and the plays you have to follow up. Example mulligan, against warlock: you are offered wild growth, druid, azure drake, wrath. In this instance, you keep wrath, because you don't have a play after wg. But if that azure drake were a shredder, you would ditch the wrath because you are a) curving out and b) need to find card draw engines (lore). The subtleties of mulliganing become more clear as you play. Just remember, it plays like a tempo deck, and although wrath is great, is usually bad early tempo. You'd rather innervate a keeper to get a body out there. I estimate success with the deck to be around 80% based on mulligan. Knowing what to keep and look for is something you will become better at.
Here are the statistics from rank 6 to Legend #8 .
Harrison Jones: As you can see from my stats, weapon classes didn't really bother this deck. The biggest argument for Harrison is the card draw, which is a major theme for this deck, but Azure Drake is superior in this regard because it guarantees a cycle against every matchup. I opted not to run both to avoid bloating the already ample 5 slot, and frankly, weapons were not a major concern. One important reason for this is that if your opponent is using their face to remove your board, they are taking in a sense double damage and are bringing themselves into range of your combo. The other side of Harrison is the weapon destruction, but as 5 mana is too late for the patron combo. Ooze is superior for this purpose.
Sylvanas: I usually put this card in every deck, including my old Mech Mage, but simply forgot to put her in and was winning so many games I never really noticed. Sylvanas is best used when behind, but this deck is meant to play from infront so you rarely would get the intended value. Rather she would be the only silence target and bloat the 6-7 slot as a 5/5 and be useless against aggro. If the meta slowed down I would replace MCT/Senjin with this card.
Zombie Chow: This is not a good card in druid. First of all, every game you want to start with 1 innervate, and/or 1 wild growth. If you're also looking for zombie chow, you're making your mulligan less consistent. You don't need a chow on turn 1 to win, it won't make much difference. However, if you get innervate or wg, your winrate goes up quite a bit. Secondly, zombie chow heals your opponent. Normally that doesn't matter, but combo druid sometimes plays like a soft aggro deck and a lot of wins come down to single points of damage off a combo or something. So the +5 is a really big deal.