Eyelash fills are done every 2-4 weeks to maintain the shape and fullness of the eyelash extensions. These appointments are 45-55 min long. Coming to the appointment with the lashes freshly cleaned and free from mascara will produce optimal results. It is best to wait 24 hours after a fill before getting the new extensions damp. Once this period is up you can wash your new extensions with baby shampoo and brush them daily to shape and fan them out for a fuller look.