Nature has not endowed tits with the ability to forage for food anywhere and anyhow, so feeding tits is essential. Other birds - sparrows, pigeons, crows - can somehow survive the winter cold by finding food on the ground, in dumps, garbage dumps, but tits just need our help. Tits can feed on any kind of feeder, but they have to make do with what they can grab from the feeder as soon as it is convenient. For the feeder to be mainly accessible to tits, it must be made in a particular way to be convenient for the bird. On
trimthatweed.com, I found a lot of advice about what kind of feeders to make.