I wear circle lenses and makeup. The circle lenses alone make my eyes look massive, and then I just use liquid eyeliner on the top lid sometimes with a small wing, white eyeliner on the bottom, and maybe a bit of black pencil eyeliner on the outer part of the lower lid. And of course curl my eyelashes and use mascara (or you can use fake lashes, they make a big difference). Theres looooads of tutorials on YouTube for making your eyes look big with makeup, check out MichellePhan, she has 1 or 2 good ones.
As for contacts, they are a good idea if you're prepared to take good care of them and everything. And make sure they're from a good brand, not random cheap ones. They are hard to put in at first, but you get used to them eventually. I have a pair of black ones and violet ones
Here's a good thread, with lots of pictures:
C I R C L E . L E N S Official Thread [beauty & fashion] - soompi forums