Hi greenfrog, in our garden we use fat balls, Buggy Nibbles the Blue Tits, Great tits, Long-tailed tits, Starlings really like these and last year I had a wintering Blackcap feeding on the buggy nibbles butthis year even though they have turned up again their is enough berries for them at the moment.
Seed I use a feeder mix which the Tits like along with the Greenfinch and Robins
and the Dunnocks pick up what as fallen. Though this is messy with the husks of the black sun flowers seeds all overthe floor. So I would suggest no mess sun flowers seeds, peanuts. Iam thinking of putting out some meal worms soon,most of the food I get is from the RSPB shop.
Take a look at this it might help?
https://www.rspb.org.uk/birdwatch/