What do you mean exactly? Like going into instances without it up, or wiping and then starting another run? Since cds reset going into instances you should always have 3 stacks before going in so that you start the fight with 6 stacks pretty much.

If you wipe, ask the tank to wait to pull.

If you’re talking about rotationally, you want aetherflow on cd pretty much asap. Here’s a few good guides to get you started: (there might be some outdated stuff in them, such as gear)

http://www.ph14basicbitch.com/smnguide.png

https://docs.google.com/document/d/1HzHDRWtvsMsWzH9ivbcFVEHAbPgfC3nhp4y0TrCa0qg/mobilebasic

https://docs.google.com/document/d/1eXWYQfyWgxnXgQx1l8wF0kNyZCfwvbdlJocLfxN_bQs/edit