@Hebeee sounds like our house. I love TK Maxx for example and have some really quirky and colourful stuff but I also live in a 1930s house and I'm sympathetic to that. We uncovered the original quarry stone floor and restored it, put back in some picture rails, reclaimed some original 30s doors from a development and we also have quite a few antiques and vintage pieces handed down from both sides of the family. It really works imho.
I always think my Christmas tree symbolises my style. A real tree with many decorations including my Victorian Granny's fragile glass baubles sitting next to decs made by the DC over the years, felt animals we made in a snowstorm when the power was out, decorations bought on memorable trips and an avocado wearing a woolly hat. It's a lot of nostalgia, memories, healthy dose of whimsy and ultimately, only things that make us smile.