Once she says yes, then it’s your job to coordinate the date. The best way I’ve found to ask her out is to first verify that yes, she does indeed want to go out with you, then to agree first on an activity, (dinner and drinks) then on a specific venue, then finally to a date and time.
This can take 15 seconds or it can take 10 minutes, depending on how busy the both of you are.
The order here is important, because if you get a no at any stage, there isn’t any confusion. If the first words out of your mouth are, “hey do you want to do dinner and drinks with me at the Radisson on Friday?” then you’re putting a lot of pressure on her. Take it one step at a time.
Another approach you might want to take if you’re pressed for time is to first verify that she wants to go out with you, then to simply take her number and call her later to coordinate. Then when you call, ask if she has time to talk, then go through the above approach.
You don’t have to try to make it flirty or fun or anything, you have exactly one job to do, and miscommunication is much worse than being boring here. You’ve already done the hard work of getting her interested in you, that’s why she agreed to a date.
What you don’t want to do is be pushy. If you get a no, suggest another option, if that doesn’t work, ask what would work for her. Be extremely patient, and if time is getting pressed, fall back to getting her number and calling later. If you’re on the phone, give her time to make up her mind. You already have a plan in your head, she’s trying to wrap her head around this new person intruding into her life.