This comp uses the Dark Star bonus to buff up powerful carries like Jhin. The comp focuses around Jhin, until you are able to hit level 9 to add in a unit like Xerath.
When you have good items for Jhin. If you have early Dark Star units early, that will help, but don't only buy Dark Star units.
Level up on 2 if you are strong and want to start a win streak.
Level up to 5 after the carousel on Round 4 if you want to continue your win streak.
If you were lose streaking up to Round 7, you can level up to 5 if you don't think you can beat the creeps.
Level up to 6 if you are on a win streak during Round 2 or level up to 5 if you haven't yet.
Win streak or lose streak, you should normally catch up to level 6 on Round 2. Roll a small amount if you are very weak and need to stabilize.
Before the fight on Round 1, level up to 7 and roll down if necessary.
7 After raptors, level to 8 if you haven't already and roll down to complete your team.
Snipers will do the most damage when placed in the corners, but make sure to scout for enemy Blitzcranks and Zephyrs so you know how to place your Jhin.
Since this comp is heavily AD based, you can throw magic damage items on Ashe, or wait until you are able to fit in Xerath.