Let's make a thing clear: you will eventually be seen as a creep by someone, but you HAVE TO. You can't be liked by anyone. Those who will see you as a creep aren't those you want to meet.

That said, the best way (imho) to cold approach someone without seeming a creep is:
"I know it's kinda random, but *anything else you want to say*".

You want to say "I saw you and thought you were cute, wanna grab a drink some time?"? Do it.

You want to say "I love your style, it caught me! Wanna hang out later on this week?"? Do it.

You want to say "I wanna meet you, my name's *name*, and yours?"? Do it.

Just state WHY you are approaching her, be GENUINE, be HONEST, be POLITE. Say "I know it's random but..." because you're acknowledging that what you're doing isn't the social norm, but you're so confident that you're willing to break social norms for her.

This is the best advice I have for you. Take care of it.