Agree with InstantClassic on this one. You're being a pick-up robot; you're relying on routine and just going through the motions instead of enjoying the interaction. It's fine to use routines, they're useful tools, but don't just go through them one by one until you run out. Learn more about natural game and become a good conversationalist rather than just remembering and repeating lines.
Once you've become a good conversationalist and having good posture and tonality are first nature, you can start to focus less on yourself and give all of your attention to the girl. If you really pay attention to her and listen then it's much easier to gauge what she's thinking and feeling, from which you can determine whether or not she's interested. You don't need huge IOI's, as InstantClassic said, many of them are very subtle. Look out for these:
- -She keeps scratching the back of her wrist or behind her ear.
-She plays with her hair.
-Her legs are crossed but facing towards you.
-When you lean back or move away she leans in slightly.
-Look into her eyes, see if she maintains eye contact.
-If she's laughing at your jokes when they aren't funny.
-She's always smiling when she talks to you.
-You take hold of her hands or touch her and she doesn't pull away.
There's a whole load more, and a lot of them are a lot more subtle than that, but you get the idea. Also note that some of them can be misinterpreted - she might just be itchy, or her smile might be fake - learn to tell the difference between a fake smile and a real one.
Just pay less attention to yourself and more attention to her. When she speaks, don't just hear, actually listen. If she says something interesting talk about it instead of going into the next routine.