Buy an eyelash extension kit. Some things the kit will include are different sized lashes, tweezers, adhesive, adhesive remover and an eyelash brush.
Wash the eyelashes. A clean pad can help you remove all makeup and dirt so that the adhesive will stick to the lashes. Allow time for the lashes to dry before applying the extensions.
Cover the bottom lashes with a white adhesive pad or tape. Your kit should include some sort of gel pad or tape to help pat down the bottom lashes.
Have your friend close her eyes and make sure the pad or tape doesn't make the upper lashes push upward. Comb the upper lashes to insure they are smooth and separated.
Squeeze out a dot of glue onto a smooth surface. You will not need a lot of glue for each lash, so a dime-sized amount of glue should be enough for a full lash extension procedure.
Grab a lash with the tweezers and drag half of it through the glue. Start at the inner corner of the eye and gently brush the extension against the natural lash where you will be attaching the extension. Slowly drop the synthetic lash onto the natural lash, approximately 1 to 2 mm from the eyelid.
Continue working your way across the eyelid, making sure to separate each lash with the tweezers before attaching the extension.
Apply the last lash on the outer corner of the upper lid and allow it 10 seconds to dry. Remove the tape or gel pad from the lower lid and allow your friend to open her eyes.