I have a love hate relationship with winged eyeliner. I used to be obsessed with it, the (self proclaimed) Queen of the winged liner, then overnight I hated it and literally didn't wear eyeliner for a year.
A reformed winged eyeliner addict, I am slowly trying to reintroduce it back into my life and the key is subtlety. You don't want a thick black line over your whole eye as it can appear very harsh and makes your eyes appear rounder, which isn't always the most flattering look. By only applying eyeliner to the outer corner of your eye, not only do you elongate your eyes but the whole look is much fresher and less heavy. Angelina Jolie is the master of this eyeliner trick and it looks beautiful on her.
To create your wing you can use whatever liquid liner you like, as long as it has a thin nib. I personally like to use a gel eyeliner with a brush. This gives me more control and gel eyeliners are pretty budge proof. My favourite are the fluid lines by MAC, here I have used Dip Down which is a brown colour. Its a nice change from black and is less harsh. My favourite eyeliner brush is actually an art brush. I highly recommend picking up a brush from an art shop as they have a much finer point.
The key to this look is starting your eyeliner at the outer corner of your iris and keeping the rest of your eyelid clear of any liner, I know its tempting to fill it in but leave it! You can extend your wing just above your crease but don't go crazy and remember to keep the line thin, we are thinking Angelina not Amy.
If you manage to bag yourself a Brad Pitt, thank me later ;)