A good technique for making candy floss (cotton candy)

For the frame, I would suggest baking a cake, brownies, gingerbread or even cookie dough in a baking sheet (so it's one big, quite thin piece). But put the temperature of the oven lower than if you would use a regular baking mold. You could also use a piece of styrofoam/polystyrene*, covered with tin foil. Then you can use tooth picks to hold everything in place. To cover the tin foil, use sour strips, marshmallows...

As glue you can use chocolate or caramel if it should sit quite steady. You can also use edible glue (this is often used to glue pieces of fondant to cupcakes). If you present it horizontally, you can use a lot (syrup, honey, jello, icing, even a thick pudding...). I think you could even melt some candy and use it as glue. I have no idea however how strong this would be.

*) I'm not sure this is the correct English term. To be clear, I mean this.

It seems the best thing to do is to have a sealed container with little air in it. CO2 has proven to be useful, but its presence is not as important as sealing.

So, if you want to preserve cotton candy, my experimental results show that a sealed container is preferred. I obtained a conservation of 24 hours, but probably it will least 48h or even more.

EDIT: Well, sealing seems to work pretty well, but I have to report a pair of failure... 2 out 5 packages did not preserve the cotton candy for more than 24 hours, while the remaining did. On the plus side, the first experimental sealed package preserved cotton candy for more than a week.