I try to find joy in the mundane, or build in joyful moments with my preschooler.
So for example, in winter, I'll make homemade gingerbread using stencils found online and make mini gingerbread houses. The kiddo then decorated her houses with cheap little candies from the dollar store or Bulk Barn. We also make pancakes into funky shapes like Mickey Mouse. Last week she was learning the letter V in her workbook, so we watched a YouTube video on volcanoes and then made a baking soda and vinegar volcano. When we go to the park, we pick up leaves, which we then paint and use as stencils. Even boring things like bathtime can be fun if we use the bubbles to make Mohawks, or bring in some plastic animals and have them play hide and seek amongst the bubbles.
Most of these things can be done with things around the house and are not expensive. It's about how you approach your mundane activities. So for example, going for a walk in the mountains is boring, but not if you look for animal tracks, pick up different leaves and learn which trees they come from, pick up rocks for crafts, etc.