I saw this idea on cricut.com and loved it. I tried it for Christmas presents for my nephew's and niece's for Christmas. I filled them with candy and a gift card. They were very easy to do.
I tried the first two with hot glue to seal and do not recommend it. Then I used Gorilla glue (which is at the craft stores. I got mine at Micheal's for $5). Some of the bottoms did not look fantastic so I put ribbon around the bottom. I recommend putting a lot of pressure on the can after gluing and leaving it on there for a least an hour.
When you are looking for cans to use make sure the bottom is not rounded on the edges. The saftey can opener(I got mine from pampered chef for under $15) will not work on it. The bottom edges should look the same as the top edges.
Also I recommend a thin scrap booking paper since it bends easily and can be glued easily to the cans. I used spray glue for the paper since it is cheap and goes a long way.
Here is the link to the tutorial I used for inspiration. http://www.splitcoaststampers.com/resources/tutorials/pop_top_can/
Add a tag with Christmas stamps on the other side on these two larger cans.
Have fun with making these. I think you will love the results.