9/10 she will go right with it. then here's that one girl who will say but I really do have to wait for my friend. Or what you said you would get:/ those women need to be warmed up and get them going with you. One reason they may be going cold so quickly is because they aren't in a setting that they're necessarily expecting to be approached by men. Another possibility is that you may (not totally sure) but you may be trying to converse and set up a long conversation when they aren't in the most social moods. If you can approach and get her number and close in relatively fewer lines, and you are in their head and they're thinking about you after you're gone, with her number in your phone, you'll get the dates afterwards. Here's a dialogue example from two days ago
Me: hey there, I couldn't help but noticing you picked out that green shirt a second ago. It really compliments those beautiful brown eyes

my names jake
Her: oh haha thanks jake. I'm Reece. You seem to know a lot about style. Which jacket goes with this top??
Me: well Reece, I don't give of these top secret style tips to just anyone
Her: but im not just anybody.
(She was being real playful so it made things easier)
Me: true true. I'll make you a deal, go out with me sometime and I'll tell you what I think about your little fashion crisis
Her: ooh that's hard to say no to but I'm going out with friends tonight.
Me: in that case, I'll just take your number and we can go from there
Long story short got her number and set up a date. The key is to get her hooked from the first words you say. Compliments always catch them off guard (in a good way) and it lets them know you are attracted to them, and you want to take them out with you. A simple I noticed your cute smile, stunning eyes. Choose your adjectives wisely and watch them be more effective

I wouldn't try to follow up the waiting for my friend line with cmon it'll be fun relax. I would lean more towards well the offers on the table reece, it's a shame seeing you left alone here. Walk with me to grab some frozen yogurt or something where you could walk and talk while she stays where she's meeting her friend.
Anyways to sum this up:
1. Greet her with something that she will remember not just hi I'm jake
2. Induce a fun topic that you can be playful with that sets up the number grab or the "date ask?"
3. Close in a relatively quick (but not hurried manor). This keeps you from chasing her. You are now in the drivers seat
4. Don't treat it like a mission. Have fun with it. Rejection is a chance to learn. If you're having fun and relaxed the more relaxed and playful she can be.
5. Leave her thinking about you, don't just say bye, find something that keeps the thought of you in her head while she's doing whatever women do
Hope this answers your question
Jake