If you're unfamiliar, tightlining refers to specifically applying pencil eyeliner to the waterlines of your eyes to make your lashes look fuller. When Martin explained to me how to do this technique, she didn't refer to the waterline but rather the very base of the upper lashes. She took my Pat McGrath Labs Perma Precision Liquid Eyeliner (£25.50) and carefully dotted the liner along my upper lash line (brave, but she's a professional). The difference was barely perceptible, but the dotting technique made an incredible difference on how dense my lashes looked. That's one of the reasons I admire Martin's makeup so much — she makes subtle tweaks to enhance her client's natural beauty.
As I was a little nervous to approach my eye with a liner that looked razor sharp, she recommended at first, I use a flat brush like Morphe's M432 Flat Liner Definer (£4.50), to apply the liner to my waterline, which worked a treat. After practising, I'm now comfortable enough tightlining using the eyeliner pen straight onto my eye.