Learn how to disrupt/escape with the flag/spear combo. Spread your AA's to make the most out of your passive. Don't trap your team with your ult. Build semi-tanky with Atma's to boost your AD (my personal play style. It works well enough for me).
Jungle him. Max flag first. If your team is tanky feel free to build damage like cleaver/triforce first(probably after upgrading machete to a madreds). If you are the teams only tank go for an early giants belt or something like that. Knowing the right time and targets to use your combo and ult in teamfights takes experience, so don't give up on him too soon!