Webinars are quite possibly one of the most potent ways you can make an exorbitant amount of money online. Russell Brunson often says that if you do a webinar every single week for a year, you'll be a millionaire at the end of it. You'll need an audience to train and you'll need to know what you're talking about. Of course, this usually requires having a website and some semblance of an online presence.
Retain some control. If you upload photos of yourself, or friends/family with consent, it's worth going for the 'rights managed' licence option – otherwise you'll have little to no control over how your images are used (eg, you could star in an ad for haemorrhoid cream). See Alamy's page on understanding stock image licensing for more on the different types of licences.
Now, if you don’t know people who might want your coaching services, there are a number of online tools and communities that make it incredibly easy to find clients and teach, on just about any topic area you can think of. Community driven platforms like Savvy.is, Clarity.fm, and Coach.me provide you with a network of potential clients to interact with, as well an integrated payment solution.