- The best question I can think of is the one you ask in front of the mirror: "Am _I_ interesting?" Keep asking that question until the answer is a solid yes… Then come up with good reasoning or examples to back it up. Big things. Small things. Silly things. Just believe them. Then, once you're at least mostly confident that you yourself are interesting, proceed to the second step…
- The best thing to do is not worry if she is interested in you[*], but instead express your own interest in a clear and honest fashion.
In the middle of conversation you might say, "Oh, that reminds me, I'm going to ____ next Thursday, that kinda thing always makes me really happy."
Then, when finishing up/preparing to exit, "You know what, if you're free next Thursday, you should come along to ____ – I think you might enjoy it, and I'd love the company."
It's not so blunt or date-focused that you seem obsessed with outcomes, but it's that nice combination of bold but subtle that will allow her to accept/decline with neither of you being offended/hurt. The main "danger" is that she might bring someone along, but even that is a chance to shine as a potential suitor, and get her friend on your side. 😉
Short of being 100% direct, this type of tactic tends to keep your social world moving, going out and experiencing fun stuff, and if done properly isn't remotely sleazy/gamey/creepy to women.
[* You're interesting, so of course she's interested. It's still not enough…]
What is a good enough question to find out if a girl is interested?