OP, I wouldn't be taking any advice from Ryuuchi on how to socialise.

If you're listening to a story drone on and on, and you want to appear interested, but you're clearly not, try to find places to ask small questions. It's important to let them finish their story however, so don't try to ask leading questions that will take ages to explain. That way you have to keep a track of the conversation, and at the same time you're feigning interest. It's best if these questions interest you, so you seem more genuine.

Example: So like, I went to the mall the other day, and saw so many cute dresses, and like I didn't know which one to try on because they were all so cute. But then my sister tells me You have a sister? Yeah.. Younger or older? Younger by like two years. Oh ok, I didn't know...go on Yeah, so she tells me to try on this blue one..

Also body language also helps. Tilting your head ever so slightly to one side shows that you're listening.

A smile also works wonders.