What to consider first

Method awareness: There are different ways to attach extensions, such as sew-ins, tape-ins, keratin bonds, and micro-links. All of them have different times of attachment, maintenance, detachment, and tension.

Your own hair matters: It is not good if you have fine, short, chemically-treated, or weak hair, since all of them cannot bear the weight of the extensions.
Right weight: Not always longer and thicker extensions are preferable. It is important to make sure that there will be no additional stress for your hair.
Maintenance matters: Semi-permanent extensions need additional visits to a stylist for positioning, tightening, or removing them.
Plan your washing routine: You still need to keep your scalp and natural hair clean. Ask your stylist which shampoo, conditioner, and styling products are compatible with your extensions.
Think about your lifestyle: If you exercise frequently, swim, travel often, or like changing hairstyles, some methods may be more convenient than others.
Check the hair quality: Ask whether the extensions are 100% human hair, Remy hair, or synthetic, and how the hair has been processed.
Budget for the full process: Include the initial installation, maintenance appointments, products, and eventual removal—not just the price of the hair.

Don't tolerate excessive tension: Extensions should feel secure but shouldn't cause persistent pain, headaches, burning, or scalp tenderness.

Know how they'll be removed: Improper removal can cause unnecessary breakage, so make sure you understand the removal process before installation.

Most important, have a consultation with an experienced stylist and discuss your hair condition, desired length, preferred hairstyles, maintenance routine, and budget before choosing an extension method