try to treat her like you would a good friend... say nonsense, just goofy stuff. Flirt with her like a 10 year old. Throw pieces of paper at her head, make fun of her when she says something weird or stupid. talk about what you want to talk about, rather than trying to hold her interest.
Another tip: often times, as long as she is halfway interested... just stop talking and look at her like you're kind of expecting her to pick up the convo. Many guys get real worried that if there is a lull in the convo, then they're messing up and it's getting awkward. It's only awkward if you make it awkward. Dont be afraid to just stop talking at certain points. I can almost guarantee that she'll just pick it up and start talking about something random. But the biggest thing here is to hold your frame. Make it seem like SHE is the weird and awkward one for not keeping the convo going. If you do this, you have to be chill and content and NOT look uncomfortable or awkward. Just chill and enjoy the surroundings until she picks the convo back up. If you have her very attracted to you already, you can even act slightly bored, because by that time SHE will be trying to impress you and get worried if you start to get bored. But i mean don't be a doosh and blatantly ignore her when she's talking about how she was devastated her brother died in a car crassh yesterday...I mean act SLIGHTLY distracted, as if you're starting to lose interest and it's up to her to gain it back.
I forget what it's called, but become good at branching off of what she's saying. For example...let's say she says "I went to this folk music festival last summer when I traveled to florida for this internship" Boom. You've got like 4 or 5 things you can branch off of without asking her interview questions:
1) Folk music - "i've been getting more into folky stuff...have you listened to Neutral Milk Hotel? I wouldn't say they're folk exactly, but they're indie-ish, youve gotta check em out!":
2) Traveling - "i went on this fantastic trip last fall to west virginia...."
3) Florida - "one time my friends and I decided to take this road trip to florida, but halfway there our car broke down and we ended up in this shady town with this dude that was...."
4) Internship - "I've been looking for an internship, but it kinda sucks because most of them aren't paid, and if i'm going to grace them with my presence, i expect to make a little money off it, you know?"
DHV stories are an easy and great way to keep the convo interesting. Try this branching technique and work in a story that makes you sound cool. Like an awesome house partied you hosted one time that got out of hand....anything really. Honestly, you can just make something up or embellish and existing story if you're a good bullsh!tter.