My dogs have harnesses. Dakota has a lovely leather one that he, sadly, rarely wears anymore. Eve has a "webmaster" harness. Dash has a little pink Lupine one but if she gets large enough as an adult, she'll inherit Dakota's old harness.
Dakota wears his harness whenever he goes somewhere with me, as does Dash. I can't use harnesses for Eve while she's working because of her cape, but she wears one when we go hiking. Otherwise it's a collar for her.