I use the Chapelwood premium Wild bird seed mix, the local garden centre to me puts in on offer in the spring so a 20kg for £10-11 (bogof) which a couple of bags does for the year. It has quite a good mix but you can top it up with sunflower hearts. The Blue/Great tits are loving this at the moment as well as the Dunnocks and the pigeons clear up whats left
The no mess stuff tends to clog up the feeders when it gets wet so i glued (superglue) an old pot saucer to the bottom of the feeder, with some holes for drainage.
It stops most of the seeds being dropped on the ground, the pidgeons and doves do a circus trick to try and stay on it to feed but most of the time it doesn't last long, so they don't take as much and are quite happy to take up the spillage on the ground.
I get the tubs of 50 fat balls (again when its a 3-2 offer) my birds love them but in my Dads garden 6 miles away they won't touch them.