I usually get the kind that has smaller seeds in it for the little birds, and then it has some sunflower seeds and other larger stuff for the cardinals and other bigger birds.
Most of what we put out this summer, the squirrels managed to get into, and spill on the ground what they didn't eat; so the birds ended up pecking it off of the ground. I even had some interesting grasses come up where the birds didn't get it all eaten fast enough; so we had to move the feeder out of the garden area. Now that the garden is pretty well done for the summer, I will put the feeder back out for the birds there, and another out front for them.