Apologies up front for meandering about a bit in this post. This was a sort of a stream of consciousness dump after playing a fair amount of ranked games with Warwick. He feels fairly strong at the moment and is fairly simple to use, which as I understand is a good combination if you want to climb.

Warwick is really good against high mobility targets as he has an ability that locks them down and holds them in place which negates their mobility. So if you see an enemy comp with lots of dashes/other forms of mobility then Warwick is often a good pick. He also does a disgusting amount of sustained damage with On-Hit builds + he is deceptively tanky in conjunction with his passive, Eternal Thirst, and Hungering Strike. The later detail will allow you to bait quite a few kills as you quickly go from low health to near to topped off over the course of a fight with a target.

What he is not is a true tank as other than draining health he has no abilities that are common with tanks such as shields, bonus resistances, or abilities that scale with health. He can only refresh his health pool while fighting, which makes his somewhat similar to Aatrox except that Warwick has point and click CC, has the ability to chase targets after the initial engagement, and has utility in the form of Hunters Call.

Don't use Infinite Duress on Jax while he has Counter Strike active. It won't do any damage to him and when the duration of Counter Strike ends or he reactivates it, it will do a boat load of damage to everyone in the area.

If you use Infinite Duress on Lux after she has started the casting animation for Final Spark, it will still go off.

Be cognizant of the enemy team's CC when going for a turret dive. If they have someone with a long duration stun/snare, think long and hard about not using Infinite Duress to lock down a champion in turret range as you will take turret shots while suppressing the target and for the duration of any CC that is applied to you while you are suppressing the target. Underestimating that has gotten me killed more than once.

You can easily do a full jungle clear with a just a Hunter's Machete.

Since you don't have any hard CC you can't lower the resistances on the scuttle crab, so it is easiest to take them when you have Red Buff which at least slows them.

When clearing the jungle use Hungering Strike sparingly. The mana cost is extremely high, so you will quickly go OOM if you spam it every time it is off of cool down. Prioritize attack speed and using Hunters Call for jungle clearing and save Hungering Strike for when you are falling below half health, unless you want to be topped off in health before a gank.

Hungering Strike acts as an auto attack reset so you want to AA + Q (Hungering Strike) + AA for maximum damage.

In ganks try to get behind your target so they will have to run through you as Hungering Strike causes you to stand in place during the animation which will cause you to lose ground on your target.

When ganking you want to try and AA + Q + AA your target before ulting them. You can also thread a Smite in there depending on your needs. I tend to run Challenging Smite via Skirmisher's Sabre on Warwick unless their team has so many dashes that you need Chilling Smite via Stalker's Blade to keep up.

Casting Smite while ulting does not interrupt Infinite Duress. If my target is high enough in health that I don't think I can kill them then I like to use Challenging Smite near the end of my ult duration as it gives you 4 seconds of vision on the target which makes it much less likely that they can juke you by going into a bush and since they will most likely be below full health after your ideal combo you will often have the speed to chase them down due to Blood Scent.

However if you think you might take a lot of damage in the process of AA + Q + AA on them or you are worried about them bush juking you and you don't have a ward handy, you can use Challenging Smite at the beginning of the process to lower their damage output by 20% and gain the 4 seconds of vision on them.

Also because of the true damage DOT from Challenging Smite, targets will quite often think they've gotten away only to drop dead with the last tick of damage from Challenging Smite.

If you have an ally present you want to thread in a Hunters Call prior to ulting the target to increase the attack speed of your ally(ies).

So your ideal combo in that case would be AA + Q + AA + W (Hunters Call) + R + thread your Smite in where you think it is appropriate.

Be with your team around objectives. The 20-40% attack speed boost Hunters Call gives to your team is superb for speedily taking down objectives.

A good Alistar will make you cry because he will never let you touch his carry. You just have to wait until he has used his CC on other targets before ulting the target you want to lock down.

Gragas can also make life hard for a werewolf. Really anyone with a displacement ability can make things difficult, so you have to watch out for those things while playing The Wick.

I've talked about this topic before, but wanted to cover it again as it has been a while. Infinite Duress has some really weird interactions with blink based abilities such as Kassadin's Riftwalk and Master Yi's Alpha Strike. I've seen everything from simply following them when they blink, to them blinking but still being suppressed and taking damage, to them blinking and not taking any damage or being suppressed at all. So in general try to save Infinite Duress for when their blink ability is on cooldown.

For an On-Hit build your item choices are generally Enchantment: Bloodrazor, Wit's End, and Blade of the Ruined King, with Guinsoo's Rageblade being an honorable mention.

2500 gold - Wit's End
3400 gold - Blade of the Ruined King
3600 gold - Guinsoo's Rageblade

So as you can see Wit's End is super cheap compared to the other items. Cheap is important for a jungler as you usually don't get much in the way of lane farm so you are reliant on kills, assists, and taking towers to supplement your income. So, Wit's End is generally a good choice, especially since you will already have a form of % health damage from Enchantment: Bloodrazor.

However, if you need the additional catch potential and you are dealing with a bunch of tanky champions it can be better to opt into Blade of the Ruined King first, especially if you aren't in great need of magic resistance.

If you have your ultimate, but you don't have Enchantment: Bloodrazor, yet, but you would like to make a play. Go to the lane with the highest amount of/easiest to hit CC + damage. Got a Pantheon top lane? Yeah, that is the lane you want to go to.

Once you have Enchantment: Bloodrazor you can solo dragon fairly easily albeit at a relatively slow pace. Bring a pink ward with you so you can clear out any vision they have in the dragon pit.