So, remember how Olaf got Olaf-ed?

You should see what he does in the jungle nowadays. Start blue, level up axe first. Grab W second for the sustain. Don't worry about fighting every single camp on the way to red buff, you will beat them and have plenty of health to survive.

The lower on health you are, the faster you attack (And gain health with W active). Start of with ranger's axe for the easy jungle clearing, after you're farmed up and ready to pick fights, switch to skirmishers and always smite whoever will deal the most damage to you. Upgrade skirmishers into Purple enchantment, Red gem might look tempting on an all out attack champ like Olaf, but the attack speed does wonderful wonderful things for him and you kill camps way too fast for the stacks not too add up.

Your early ganks will be none-existent, you're going to be hard farming in the jungle, and going back only when everything is dead. Makes sure your team is aware. After about the second full clear of jungle, start roaming into lanes and just being a general jerk, throw axes at people, smack them with true damage, walk away. Never commit to a tower dive unless your laner can tank it. As long as you gank cautiously and stay farmed up, you will be able to pretty much 1v1 anyone on their team with a challenging smite against them.