Is there special preparation before getting eyelash extensions? Yes-Please shower ahead because lashes must remain dry approximately 48hr after applying. Eye makeup should be removed before appointment if possible. Are there special products to use with eyelash extensions? Oil-free makeup remover should be used for makeup removal. Should any activities be avoided? Yes. Underwater swimming should be avoided. How often are Lash fills required? Although lashes can be whenever desired, most clients find that every 4 weeks works well to keep lashes full and fresh.