High-ticket consulting or coaching: You could sell your own high-ticket consulting or coaching products from your website. You'll still need a website, merchant account, sales funnel, lead magnet and many other items. But you can easily earn a substantial amount of money from each individual customer, making it well worth the arduous setup required.
Work remotely for a call center. Because many call center jobs are location independent, finding work in this field is an easy way to earn some money from home. Dozens of sites list job openings for call-center representatives, including Freelancer.com and SimplyHired.com. Meanwhile, you should check local job listings for openings and opportunities as well.
Not only that, you will be able to evaluate business ideas much more intelligently once you've gone through this whole process. You will understand the fundamentals of keyword research & analysis, traffic & lead generation, social & affiliate marketing, monetization & conversion testing, and traffic analysis. These skills will help you immensely in ANY business you ever decide to start (online or not, passive or not).
Whether you have a website or are still dreaming up ideas for a blog, you can also look into affiliate marketing. With affiliate marketing, you partner with brands and businesses within the content of your website. If you mention a product or service, you link to that produce or service using a unique affiliate code you received when you signed up for that particular affiliate program. From there, you’ll make money any time someone buys a product or service through your link.