Pros: Reduces armor with Q, is invisible with W, jump towards enemies with E, knock them up using R, easy ganks, he doesn't need kills, counterjungler, low cooldown.

Cons: He has got problems in early game with attack speed junglers, ganks are not really good pre-6 level.

As you can see, most important runes are three flat cooldown reduction glyphs.
http://scr.hu/20ai/nvcq7

I think those masteries are the best but if you have better idea, comment :)
http://scr.hu/20ai/wgn89

Items:
Start with Matchete, 2 Health Pots and Trinket,
Core items are: Blue AD (red) matchete, The Brutalizer, Ionian Boots of Lucidity and Ravenous Hydra.
Then buy: Trinity Force, The Black Cleaver or Maw of Malmortius.
At the end: Thornmail (vs attack speed), Randuin's Omen (also vs attack speed), Quicksilver Sash (vs Warwick), Guardian Angel or Banshee's Veil (vs AP).

http://scr.hu/20ai/27sox

You can also take W on second skill.

ALWAYS take SMITE + FLASH (smite you know because jungle and flash you can use while you are ulting and you can't use E while ultimate).

Use E then W, make sure that monsters are hitting your clone and use Q to attack them. Then repeat the sequence :)

At the end of bush, use W: now opponents can see you, jump un them using E, reduce their armor (Q) and knock them up (R). Then give kills to your teammates :)

In teamfight do same seqence as in normal gank. If enemies will run away and you will ult, don't forget to flash! Always iniciate the teamfight.