Whats te best way to complement a girls eyes?

usually i say dam u got some beautiful eyes sweetheart, or them are some pretty girls, but i dont know it dont sound right to me. u think im thinking bout it to much. i also complent them on thier clothes like for instance ill say u look sexy in that shirt or u make that shirt look good. i once told a girl she can make a burger king shirt look sexy, so this question is for all the pretty women out there u think im thinking to much and this is fine