Assuming you have done your research to find a skilled hair extension stylist, please start with a consultation. Be open and clear about your expectations, lifestyle, allergies, and any issues you had with previous stylist and extensions. Ask questions, a lot of them. Question should include how to treat your hair before and after the extensions are installed. This includes washing and conditioning your hair, restrictions on physical activities, and exposure to moisture and heat. Another very important question to ask when having extensions is if the stylist requires regular maintenance appointments (usually between 4-8 weeks). Make sure you have time to attend these appointments to ensure the longevity of your install. By the end of your consultation you should feel excited and comfortable about the service you will soon receive. Best of luck.