Are you sick of untaping your client, having her sit up only to realise there is a gap or some lashes not sitting quite right? Every lash artist should have a dental mirror!
Use after taping up and during application to ensure the waterline of your client's eye is sealed tight. This stops tape or gel pads from creeping up and cutting eyes, or your client getting a chemical burn from having adhesive fumes seep into their eye.
Separate lashes at the end of the procedure and look through the mirror to ensure there are no gaps or wonky lashes. This way you will know that they are going to look amazing as soon as they open their eyes!