Have someone leash golems for you, its possible to do without. but it sure helps by the time you get to blue buff. after gettting blue buff, recall get sword, then go to golems again and then red buff to get lvl 4. (gank if necessary) but not till lvl 4. then get wraiths again and get lvl 5 go back get madredz and take more jungle... jungle turns into a piece of cake once you have madredz razors
Ganking with renekton*
Ganking with renekton is super effective at lvl 6, pop your ult in a bush... wait there for about 3 seconds to get your rage up. ping a target and go for it make sure you have at least 50 rage so you can get your 2 sec stun. other wise its a waste. if you do this.. you will more than likely get a kill.. if needed tower dive and finish it... renekton turns into a tank when he uses his ulti just be sure you can get out after with slice and dice
when being a renekton you get focused alot... because your such a high threat to the enemy team. be sure to get this. when you are in ulti form you come back with your additional health. this item has saved my live multiple times.
Sunfire, spirt Visage
Sunfire i see alot of renektons get... its a good item... not his best tho.. so i save that for later game, spirit visage is great for the CD, (if you don't have runes.) if you do.. get something that will either make you tankier or deal additional damage... its all up to you and how you want to build him. i generally finish off my build with a Blood thirster because renekton can farm really easily and that extra lifesteal is pretty amazing