Some are comfortable with thin sharp nib and a tight grip while some are with the soft, loose grip, Right? Gel line usually comes in a small pot and you will need a liner brush to apply it.
Blend primer or concealer across your lid, if you haven't already.
Okay, so moving on to how you achieve this look.
You may find that an angled brush works best for applying the liner.
When placed close to a lighted flame, it will start to melt.
Then, fill in the wing as needed.