I'm happily married, so I don't really plan on asking anyone out. However, if I was single, I probably wouldn't be adverse to doing so if I felt the person I was interested in was truly compatible with me...and was single. I really feel that it can be done without coming across as though you're hitting on them. If you like someone and think that you'd like to know them a bit better, perhaps casually offer to buy a takeaway lunch that you can share together in a local garden. If they're interested in you they'll grab the opportunity to share some time with you...and it won't be too hard to arrange a further date, whereas if they're not, you won't waste your time and money, and lose face. You could also do something together that you both enjoy (bushwalking, see a movie, etc) as you'll both enjoy yourself, regardless whether you develop a serious relationship or not, and it's a lot less intimidating than asking someone out for a romantic dinner.