Level up to 4 early if you want to start a win streak. Level up to 5 to try and continue the streak.
If you're weak in the early game, you can opt to save gold and lose streak instead. Level up to 5 at Krugs if you don't think you can beat them.
At Round 2, level up to 6 regardless of your start. Put together the strongest team you can.
At Round 1, level up to 7. Roll down to stabilize your comp if you are weak. Afterward, save up to hit level 8 and complete your comp.
Cultists and Assassin transition well from the early game. Twisted Fate can hold Morgana items while Diana can hold Talon items.
Ideally by now you will have the ideal Chosen Janna. With this, you can look to add in Enlightened with an mid game unit like Irelia.
This comp can be difficult to transition into since Enlightened units don't fare well in the early game. As such, run any strong units you find early to eventually transition into the comp.
Janna with Blue Buff is extremely powerful if you find her Chosen. This allows her mana pool to decrease, making her cast very often.