Almost everyone needs coffee these days, and almost every bird needs to eat. Two great desires are satisfied in this DIY that anyone can build on the cheap.
NOTE 1: I usually recommend avoiding disposable coffee cups altogether. But if you do buy one, here's a way to get some lasting value out of it.
NOTE 2: Black (Oil) Sunflower Seeds are an amazing source of protein for many back-yard birds.
Step 1: STEP 1 - Drink A Coffee
The beauty of STEP 1 is how good it tastes, and how any size cup will work. Small, Medium, Large & even Extra-Large. Drink it all up and don't leave any drips around. Birds don't like coffee... especially the decaffeinated kind.
NOTE: I have heard that this will also work with cups that have had TEA in them. I haven't tested this out myself but it is plausible <grin>.