Need help/advice

[paperhurts.livejournal.com]

I want to make a briefcase for a friend of mine, kind of like those old suitcases where people would put the stickers on them from all the places they visited, except for this one put small versions of all the old vintage travel posters she likes (but has no room for on the walls of her tiny studio) all over it. How would I go about doing that? If they are postcards/small photos would I do something like decoupage glue? Shellac? I don’t know what kind of bag I’m getting for it yet, hard or soft I mean, but does anyone have any suggestions?