Bird seed mix - recommendations?

My first sac of 25kg of bird seed mix gone (and the season is nowhere near the end yet). So I am about to stock up. I was wondering if anybody can recommend a good mix - the one that just finished was the Beaks wild bird food but I noticed the birds threw away enough undesirable parts which I then had to clear off the grass on a daily basis (some of it sprouted too ...). I am looking for a good seed mix to use as a staple food (sultanas and corn won't go wasted) - I do add extra sunflower hearts, dried mealworms and the three varieties of suet pellets (berries, insects and worms). Main garden visitors: pidges galore, magpies, house sparrows, wrens, great and blue tits, goldfinches, dunnocks, robins and last but not least starlings. Mr and Mrs Woodpecker also do us the honour of visiting the establishment but they are hooked on the nuts it appears.