I've traditionally avoided seeming 'creepy' by blatantly violating various unimportant norms early in relationships. People don't like feeling deceived, and they don't like it when they are shown to be wrong after assembling a model. The trick is to make it clear from the outset that 'this person is extremely hard to model', or 'this person doesn't fit into any of my prefab models'. That way they don't get irritated about being wrong, they just assume it's par for the course.

Examples of norm violation:

• I am male and maintain a prominent 3 foot long braid which I often wrap around my neck

• I make childish faces at people and things

• My default vocabulary is apparently pretty exotic

• I don't flinch and easily participate in sexual topics when they come up

• I squeeze in comments about how the human race is going to fix this 'death' problem whenever I can

• When asked occupation, I say that I started as an engineer, then started a video game company (wtf?)

• When asked belief (common in the US), I state 'true nihilist/atheist' and that I'm quite possibly the least spiritual person they will ever meet

All this stuff combined generally jams up people's predictors to the point where they give up on being correct, which largely fixes the creepy problem. Most people have stuff like this available, the trick is to emphasize and export the pieces which generate the most conflict with existing models.

Be aware that there's also 'sexually creepy', which is a whole different ball of wax. Openness and being comfortable with sexual topics helps tremendously. It's also a very good idea to focus your attention and eyes on faces, not reproductive hardware, when you interact with someone.