I'm interested in a coworker in another department.

What are Do's and Don'ts for picking up coworkers? I'm leaving this job soon anyway, so I have no worries about relationships in the workplace.

She's only been around a few weeks and mostly we just make small talk. I want to see if shes down for hanging out/lunch/#-close, but I haven't found a good time to bring that up while we're working. I think part of my AA is I'm having trouble getting out of a professional mindset. Any tips on that?

Thanks for any and all advice!