Don't buy things you don't need.
Replace things less frequently. If you keep things until they need to be replaced rather than when "it's getting a bit old" the chances are you'll save money in the long run. Especially where appliances are concerned, if you can keep an old one running from when they were made properly you'll save buying a new one every few years.
Spend the money on quality when it makes a difference. If you buy the cheapest option for anything other than single use you'll probably end up buying twice.
Make good use of time and money. It's amazing how people can afford $999 for a new fruit phone but can't afford $250 for an evening class to learn a new skill, and how people can find enough time to binge watch Netflix but are somehow too busy to read a book or watch YouTube videos so they can fix simple home problems without having to call in and pay a professional.