Work is a way of test-driving a potential partner (ie getting to know them) before taking the plunge and asking them out. Etiquette: Dating a work colleague requires a good amount of old-fashioned social etiquette, not because it will make you any more attractive but because it will make the whole process a lot more comfortable and a lot less difficult, if and when the whole thing ends. Working with someone means forging an effective relationship.
Better still, you'll be seeing them during the day, rather than just propping up a bar with them in the evening. Work together during the day, pop out for a quick drink after work, Bob's your uncle. Everything is in order, from stress-busting massage at the desk to on-site counselling, so why not pick a mate there too? Hinting that you would like to take things further but never being specific can make the whole relationship uncomfortable, especially if it's a boss/employee situation.
Be polite, open, honest, and assertive, not furtive. And never be lewd (good, old-fashioned word) or make a pass.
How about: "Would you like to come out for a meal with me tomorrow night?
You know you will have at least one thing in common, as well as an informed ear to bounce all your troubles off when you get home in the evening; 2.