I own Black Ink (black) and Espresso Ink (dark brown) long-wear gel eyeliners. Once applied, this gel liner looks like liquid eyeliner, but is much easier to apply as the colour glides on very smoothly. It is long-wearing and water-resistant, and stays on without smearing, creasing or flaking during the rest of the day.
Personally, I find a gel eyeliner easier to apply than liquid, as gels take a little longer to dry, giving me time to fix any little mistakes or uneven lines. Liquid eyeliner is more unforgiving as it dries faster and can be a little tricky to apply and you need to have a much steadier hand (which I don’t have).
I do find this eyeliner to be quite expensive, even though the pot lasts a long time, and it does start to dry out after a few months. My eyelids also feel a little irritated towards the end of the day, almost like the gel liner is sucking all the moisture out of my skin, and my lids look quite red and sensitive after removing the gel. I've tried various make-up removers, as well as oil cleansing, and it's not a reaction to the remover or the way I take it off, as this doesn't happen with other long-wear gel or liquid eyeliners.
Apply with an angled brush for a thicker line, or a fine eyeliner brush for a thinner line. If you do make a mistake while applying gel or liquid eyeliner, simply dip a cotton bud or small brush into some eye make-up remover and use this to erase your mistake without having to remove all your eye make-up!
This is my go-to gel eyeliner, I find it really easy to apply and it lasts well. It's a bit of an investment, but for the ease of use, I'd rather pay a bit more! I don't regularly wear eyeliner so its handy to have a product I know will apply well and be long wear. I have it in Black Ink (1).
Tips: Invest in a good angled brush for use with gel eyeliner - it makes the world of difference when you're applying it!