Warwick is a drain tank which mean that he is tanky but also is able to regain that health in a moments notice. His passive does extra damage to any unlucky opponent and it heals Warwick for the same amount. Building sustain items and items that do extra damage with basic attacks is just second nature to this drain tank. Once you get your ult just wait for the opportunity to use it, when the opponent over pushes make them regret it. If no-one is over pushed you can try and take a lane with an allies by using Hunters Call to increase you and your allies attack speed against the turret. If that is not an option look into slowing down your opponents jungler (if they are building feral flare or need buffs) Take some of the big monsters to make it take longer or stealing a buff is never a bad thing. If you think you have enough sustain try to take on Dragon. You will have your hands busy so keep up your map awareness and you will do just fine.