I'd definitely suggest avoiding a black eyeliner. Black eyeliner can look unnatural or bad if it isn't applied properly. And it's often used to make eyes "POP"/seem larger... I'd suggest a brown eyeliner. It looks more natural and you won't notice as many imperfections.
As for how you apply the eyeliner, I think it would look best if you apply pencil eyeliner on the bottom waterline, and gel eyeliner on the top. Pencil is generally the easiest to manage and take off if you make mistakes. Gel eyeliner, applied with a brush, is 2nd in difficulty. And, last but not least, we have liquid eyeliner. Liquid's usually the most vibrant, noticeable and lasts the longest.
Here's a tutorial on how to apply eyeliner (pencil, gel and liquid). It takes you through step by step.
