Start with Krugs to get your auto attack stun. This will help your sustain on the first path and clear every camp. I like to pick up red buff next, and then smite the razorbeak to get the ward finder.

Then i move into river and look for an early gank, kill the scuttle, and try to find a ward.

Then head straight for blue buff and clear that side as much as you can based on the game.

After that the path will change with the pace of the game, but that's usually how I start.

1) Move in close enough to land your flag and get the knockup on the gank. This is super critical and if you miss you may want to just back off, because you may not have enough time to finish your target.

2) Gank for your ad champs first if possible because you will help reduce your opponents armor.

3) Don't be afraid to blind invade to avoid a ward spotting you, as you can jump over walls and flag and drag out of trouble from the enemy jungler.

1) In a full teamfight, you are one of the best at getting to the back line. I often use my flag & drag to pop up the enemy front line and drag my self closer to the carries and then I ultimate immediately closing in the enemy ADC or Mid forcing a flash or a an easy kill. Make sure you also pop W right away if your trap them, so that the slow is on them even if they flash, keeping them close enough to chase. This is why I like to max W second.

2) make sure you keep your Q on the tank, and shred the armor so your team has an way to chunk him down.

3) Your flag gives attack speed to your team, so keep it in a place where they are picking up the bonus. Jarvan is your best friend in a teamfight, as long as you keep these concepts consistent.