After reading recent posts on dating in the workplace (here and other subs), consider the gender-swap rule: would you date your males coworkers? Then don't date your female coworkers. Would you tell a male coworker he looks nice? Then don't tell a female coworker she looks nice. Would you buy gifts for male coworkers? Then don't buy anything for your female coworkers.

Treat the women as objectively as you treat the men.

There you go ladies, eQuAlItY. At work, everyone is an NPC.