Most Helpful Girl
If the conversation flows nicely that's a good sign
I look for eye contact, physical touches, if he initiates conversations /plans, if he talks about future plans as if I'm going to be there [especially stupid stuff that seems routine and not like just a date]
If he opens up about something personal that's also taken as a good indicator of his interest in me
Most Helpful Guy
Girls can be tricky to read sometimes, and honestly, can be misleading. If you like a girl and you're not good at spotting signals, the best advice I could give you would be to try to be as direct as possible with them. If you've asked them out, they are probably at least somewhat interested, if you haven't, just take the leap. There's no easier way to find out if a girl is interested in you than to come straight out and say it to them. But, if you're too shy to go in blind, look for the more obvious signs, look her in the eyes, what is she looking at, is she giving you her full attention, is she smiling, is she touching you or getting close to you? There's a lot of ways to know if a girl likes you, but none are easier than being direct.