The longer you wait, the more awkward it becomes

I do this all the time.

This one is actually very relatable. It's better than rudely interrupting.

I slowly walk in between the person that they are talking to and stop directly in front of them

Isn't that's what you are supposed to do?

I was gonna return a book I borrowed to this upperclassman but he was standing and chatting with the teacher so I just stood there with the book in hand directed towards him. My classmate got tired of the scene pretty quickly and fucking yanked the book out of my hand, pushed onto the guy, took my hand and dragged me away.