1) Visit the restroom before your appointment. (And lay off the lattes right before.) Seriously. It sounds weird, but if you get a full set of lashes (like I did), the appointment will take two to three hours. That's a long time to hold it, and it's not exactly easy to get up and hobble to the ladies room when your eyes are covered with pads and glue.
2) Make sure you have the right eye makeup remover on hand at home.Counterintuitively, removers containing oil (versus oil-free) are what you want to use. Avoid anything with PEG (Polyethylene Glycol), Hexalene Glycol, Butylene or Propylene Glycol), which are often found in oil-free removers—they can break down the lash adhesive.
3) Don't schedule your appointment the day before a beach vacation—or a big date. You can't get the lash extensions wet for 24 hours. That means no swimming, showering, hot tubs, or steam rooms.
4) Cancel that facial. Unless you really trust your aesthetician to steer clear of your eyes, beware. Excessive tugging or pulling (not to mention all that rinsing) will shorten the life of your lashes. Better safe than sorry.
5) Stock up on facial cleansing wipes. Turns out it's really hard to wash your face with traditional cleanser without getting your eyes wet. (Doubly hard if you also happen to have a blowout that you're trying to preserve, as I learned last night...!) A stash of makeup removing towelettes will make your life a lot easier.