Make it round-style, like the commercial galvanized or plastic feeders, and they work fine. All my feeders are homemade in this way, from buckets and small trashcans and such. No complaints
The hardest part is finding an appropriate pan for the bottom. It needs to be about 2" deep, and about 3-4" wider than the bottom of your trashcan/bucket/whatever.
Then you cut holes (I usually make them triangular) all around the bottom of the trashcan/bucket/whatever. They should be not quite as tall as the bottom pan is deep.
Then you either just set the traschan (full o feed) inside the bottom pan, or if you are feeling ambitious you can poprivet (for small feeders) or bolt (for large feeders) the two together.
A lid or cover is a good idea as well.
I don't think I have any pix of mine but they're really really easy to make. (e.t.a. - you don't need any special device to prevent dead spots -- just let the thing go nearly empty before you refill it, then on your way to refilling it tip it to one side so that the very small amount of feed left in the middle of the trashcan/bucket/whatever floor is tipped out into the rim area where it will get eaten)
Have fun,
Pat