Line them close to the lash line with Chanel, Marine eye pencil. Use a blue undereye concealer (under foundation - of course)
and before putting on your regular mascara rub a navy blue color on the edges of your top lashes. Use black mascara on top and brown on the bottom. Put a small dot of white at the inner corner of your eyes and a very pale lavender dot in the center of your eye over the iris as a highlight.
I have blue eyes too and I find that metallic colors work great. Golds, bronzes, and colors like that really bring out the blue in you. If you dont think the metallic hues are for you try natural brownish-coral colors. Almay has a line of eye intensity eye make up that is awsome.
Black eyeliner is the classic approach, but if like me that looks a bit too hard on you I would really recommend using grey eyeliner instead! it's a softer look and it makes my eyes look even more blue!
Everyone says my blue eyes are piercing, apparently. All I use is a thin line of black eyeliner across top of my eyelashes, and leave the bottom ones and just use mascara. Does wonders!