I believe in dps jungle blitz due to him not having a good lane to go to.( bot he has to support no cs no items, top he isnt to good cause hes best with a partner to use his pull and have him and his partner attack the enemy, and mid he has no range so farming he will have difficulties) Thatw why i jungle beacause he can also gank very well. I go dps beacaus his q and r have high cooldowns so even after u burst them they can easily attack you, and for dps i found out your e can crit and having atttack speed with his w makes him have high atttack speed.

I chooose standard ad runes working critical chance, attack damage for his e and physical attacks.

i go 21-8-1 for improved damage in offense, tankyness and improved smite in defense, and 1 in ultiity for improves clarivoyance.

I choose standard heavy ad items like phantom dancer, blood thirster, infinety edge. And manamune for ad and mana which he needs for mana barrier(his passive) and because he is mana hungry with his q costin 140 mana, then tri force for the health damage,mana,crit,attack speed, movement speed and especially the slow and sheens passive.

i max q 1st for its extra 60 damage each level, w after that for the attack speed buff, and e last because only cd increases when u lvl up e.

i choose clarivoyance and smite because wothe clarivoyance u can use to see where to pull and smite is a good jungling tool, especially for a champ like blitz who excells jungling for the ganking aspect rather thatn the aspect of killing jungle creeps.

i start at blue(get leash proably 2-3 hits), then go to wolves, then perhaps gank or if not ganking go to wraiths then small golems and then gank(please note if team asks u to gank or cover lane at any time during ur jungle route, just beacuse i didnt say to gank/cover lane at that time u still can depends on game.

remember blitz is a good intiator with his pull so tend to intiate fights by pulling an enemy champion into ur team which usually is a free kill.