In winter I used to hang 'fat balls' in the pear tree, but the birds were not overly keen due to the cat being able to climb up and watch/eat them (birds, not fat balls).
This year I've hung them from the metal vine-holding construction (what is it called? - can't remember, but can't recall much this morning due to head being full of cold residue) at the front of the house.
This is good! Great, in fact. They can't see us, and we can see them. There's a sort of air-traffic control system of stacking in place now. Each fat ball has usually two or tree birds (tits of all sorts, sparrows, nut hatches, and once a wily starling) attached to it, while other same-specie birds wait on the bare branches above and around. A second layer of birds hop around on the flower pots - sparrows, robins, dunnocks etc picking up 'fall out', and on the ground: blackbirds, thrushes, robins, starlings and occasionally, magpies peck at grain and toast debris.
For the price of a cut price DVD a bag of fat balls provides them with food and us with endless enjoyment at their ariel acrobatics free of cat threat.