So lately I've been buying Suet Plugs, essentially tube-shaped suet, and feeling like it would be ridiculous to buy a feeder for them. This is because a suet plug feeder is pretty much just a log with holes drilled in it. So, I made my own. This is super straight forward:
Take a log, ideally about as thick as the plugs are long (definitely not thicker, though thinner is ok). I used a section from last year's Christmas tree. I'm not sure what treated wood would do, but I figure better safe than sorry in terms of not poisoning the birds.
Screw in a hook at the top of the log.
Put suet into holes (make sure it is mushed in and won't fall out). Hang on bird feeder.