Mundane stuff is only mundane when you are doing it. When other people read about it, years later, it becomes a treasure trove of your daily life, something that they would never get to witness or even think about if you hadn’t written it down.
I just read a book that was basically an (fictionalized) account of one pioneer woman’s trek across the country as a new bride, walking across the United States, following her husband while guiding their meager belongings in the wagon, and trying to stay alive in the face of many dangers. The book is called The Diary of Mattie Spencer by Sandra Dallas. She talks about cooking outdoors, making paletable meals out of the most meager subsistence, talking and laughing with her husband, and describing what she sees and hears and feels. It was breathtaking and mesmerizing.
I would suggest that you take 5 minutes out of your day, each day, and simply write about what you did, who you saw, who you spoke to, what kinds of tools/appliances/electronicdevices did you use. Did you go to the store? What did you buy? Did you walk to the mailbox? Who and what did you encounter (dogs, neighbors, potholes in the sidewalk, a nice cat). What did you have for breakfast/lunch/dinner? How did you prepare those meals and did you encounter any difficulties or amusing moments? What is outside of your home? Do you see birds or squirrels or neighbors or a yard that needs to be mowed or beautiful roses in your garden? What does it smell like? Do you smell water hitting the hot pavement in summertime? Do you smell smog? Do you smell the rain coming? Do you smell the snow on the wet earth?
Just tell it like it is. Don’t try to pretty it up.