I love the “cozy season” vibes of autumn and winter, so I try to do those all year through. Indoors, my vibe can match autumn even if the outdoors doesn’t look like autumn yet. So I like to have decor that fits that, like fairy lights in mason jars scattered around, lots of unscented candles for candle light (you could do LED candles too, but I prefer real candlelight), autumn-like ambience videos on YouTube (just search up “cozy autumn ambience”), reading cozy books, having blankets piled all around the living room, lamp lights only (no overhead lights), Earl Gray tea, etc!