Water... I just keep changing it every couple of hours. Empty it every night, refill in the morning and repeat.
Sultanas, peanuts, mixed seeds, black sunflower seeds, fat balls plus blobs of lard (with seeds and stuff melted into it) - all in large quantities.
Squirrels give my garden a wide berth though if they were reds they'd be more than welcome, sadly just greys here.
We have blue tits, great tits, willow tits, coal tits, long tailed tits, dunnocks, sparrows, starlings, pheasants, woodies, collared doves, woodpeckers, chaffinches, greenfinches, robins, wrens (though not feeing), blackbirds, thrushes (song and mistle) and that's about it.