Remember how in Pretty Woman Julia Roberts' one rule was, "No kissing customers"? She was a smart woman. She knew that setting something off limits was a way to maintain boundaries, and remind Richard Gere of the limits of their relationship.
Take notes on Julia's technique. You should maintain some level of detachment from the woman in question and draw some lines. For example, if you don't want a relationship, you should probably not spend several days a week together, have sleepovers every night, or make her dinner. Think about which actions might ultimately make your intentions unclear, and eliminate them.