+1 on using nothing but suet and black oil sunflower seed. I buy a 40lb bag at the farm store for about $15.00 and put it in a feeder designed for it, and it lasts a couple of months. I also have a finch feeder, but I’ll probably not refill it since the finches seem to be just as interested in the sunflower seed as the much more expensive thistle seed. The sunflower seed feeder is like a cylinder with screens on the side and a perch on the bottom, so birds will pull it out one seed at a time without scattering a bunch on the ground, and it attracts both clinging birds like goldfinches and perching birds like cardinals.
If you like bluejays, you can get a 50lb bag of cracked corn for less than $10. Or feed the squirrels whole corn and birds will come pick at the remnants.