Depending on where you start, you clean the jungle from the bot lane. After Red/Blue its good to invade enemy jungle. If you're low on health, kill the Rift Scuttler plus you'll get some vision too. Gank as often as you can. You can clean the jungle easy on every lvl with almost no health at all. Hunter's Potion will help you stay on the map very long.

If the enemy jungle isn't a tank, you should probably win every time you meet.

Poppy can solo drag from lvl 6 with proper items, so keep that in mind. To do it fast I suggest waiting for lvl 7 or 8. Or you can always ask for help from bot. Rift Herald is also a good idea if the top laner have a while to help you.

Poppy can do very well without blue so its a good idea to give it to mid laner.

Poppy's passive is very useful in jungle. You should pick the buckler as often as you can, so you'll avoid tons of damage.

Q does some damage over a while so keep that in mind, it works very well after using E.

W has two effects:
Passive - gives you armor and magic resist.
Active - It gives you movement speed and BLOCKS dashes to you and (if you are close to enemy) away from you. It really can screw up some of the champions while it doesn't work on others. Ezreal for example. Also it doesn't work on Flash effect.

E works best if you pin the target down to the wall. Champion or monster will be stunned.

R looks amazing, I know, but it's also awesome way to escape from the fights. If someone chases you, use R and hold it for a while then release. Ult also works very well for dealing damage or CC the target(s). In that case use R and release it very quickly so the targets will only jump in one place.

Use E to stun, then use your Q, and W so enemy won't escape. Now is time for Smite and if the target is not dead by now, you can finish him of with R.