I play mainly Grux jungle and have been having some decent success with him.

1) I start with a health pot with a madstone gem that i upgrade fully (only 5Cxp total) after clearing ALL the white minions (that means both right and left). You should be able to do this by kitting jungle minions.

2) After the madstone, I get a ward depending on your preference I would suggest brawlers ward or guardians ward, that you fully upgrade (6 Cxp total)

3) After that go into a Windcarver fully upgraded with 6 Cxp and an Adament's Edge fully upgraded with 6 Cxp. At this point you've spent 24 Cxp, but you have around 100 power, 11 Attack Speed and health or mana depending on the ward you chose. Needless to say that you will be hitting harder than an adc at the moment and can easily kill Casters and/or Adc's.

4) After that, depending on the enemy team, mostly on their offlaner, I go with a Armor Item that i will fully upgrade with 10 Cxp.

5) After I proceed to replace and upgrade the early items I've had and at the end I finish with another Armor fully upgraded with 10 Cxp.