Bump codes don't seem to work anymore. Best way to do it is to smoosh. I'm of two minds on this topic - as a seller, I prefer to keep them sealed so my buyer knows that they are getting a minifigure that is completely brand new. This also lets the buyer have the fun of opening the bag. However, as I buyer, I want to know that I really am getting what I paid for. I want to see that it's really that mini before I buy it. Because of that, I'm leaning toward opening minifigs and immediately sealing them up into plastic bags. I've got a ton that are sealed, but I almost feel better knowing for sure that I've got the mini I think I do before I sell it. Just in case I've screwed it up.