If I cut shapes from a soda can, How do I round edges to make them safe and.?

.how to glue aluminum can pieces together? Which type of glue would that be?I know die cuts sort of do it automatically but I am using razors or scissors.

I would sandpaper the edgesAlso, definitely use hot glue as it will give the best hold and be almost instantBut as the other person said, be careful.