This is so quick and simple you could do it in one weekend.
What we did was collect the fat from our frying pan (Steve's sausages etc) and pour it into a yoghurt pot. It took us around a week to fill this little pot but it depends on how much meat you cook and how many people you cook for.
Simply stick a skewer in the fat then either tie a piece of string around the yoghurt pot or slide the mass of fat out and hang in a tree or fence pot.
Voila – homemade bird feeder.
PS – I'm dying to tell you all about my new bird feeding/housing station – keep popping back and I'll tell you about it soon!