Tips for Hecarim Sparkles?

Hai people!...I like hecarim, I think he is pretty cool and stuff but there is....a lil problem...

I SUCK AS HIM! (jungling) I allways fail my ganks, allways ends up with me watching the enemy run away.....or him getting a double kill in case its a fiora ._.

plz someone give me some tips to at least do my proper job as jungler and maybe some tips for Teamfights

Ttttthank you very much! :D