First collect some old yoghurt tubs.
Cut a small piece of dowelling (or a lolly stick) the size of the base of the yoghurt tub and tie a longish piece of string to it. Wedge the stick in the bottom of the yoghurt pot with the tail of the string coming up out of it. When you pour the fat mix into the pot, make sure the stick stays at the bottom and the string is trailing out of the top. When set, you can turn it out like a lolly and hang it up from the string.
You will need some fat for binding the mixture. Lard is very cheap and a big block will go a long way.
Melt the lard in a saucepan until it is liquid - but not too hot (beware too much heat as you will end up with a pan of smoking oil!).
Cool a little and add some mixed wild bird seed, raisins, unsalted peanuts, and any small pieces of leftover cake or bread (not too many of these).
Then pour the mix into the old yoghurt pots.
Allow to set completely and then hang out for the birds in a place where they can eat safely away from predators.