However, you should pick a niche and blog about that. If you're launching a money related blog, maybe it'll be about how to make money in real estate or simply how to make money online. Pick the niche and stick to it. If it's a diet and fitness related blog, maybe the niche is the Ketogenic diet, the Atkins diet or some other form of diet or fitness.
Also, if you pursue an income stream like affiliate marketing, your blog can be a source of content that allows you to link to affiliate sites in a way that is seamless and natural. For example, if you are an affiliate marketer for a company that sells productivity tools, you can blog about your own struggles to stay on top of your to do list. Then, you can mention how much those tools have helped you.
If you have specialized knowledge in a certain topic, you can put together an online course to teach others. For example, if you have experience in real estate investing, you can create an online course “Real Estate Investing 101”. The benefit of an online course is that once you create the course material, you can sell it to as many people as you want.