The best validation is a deep understanding of the target group and their problems. Let me give you an example.<p>First, pick the target audience you are either part of, or familiar with. In my case, I chose new and aspiring managers.<p>Second, learn about their pains. Talk to them, see what they discuss on Reddit, Quora, and wherever else they gather. In my case, I see questions about communicating and dealing with difficult people and dealing with various corporate processes.<p>Third, figure out what they pay for. Some groups buy books. Some pay for SaaS. Some prefer webinars, screencasts or courses. The options are endless, but the focus should be on what the customers already buy, not what we can easily make. In my case, new managers often buy books.<p>Four, pick one pain and fix it. Now you don't really need validation in the conventional sense of the word because now you _know_ what the people want and you _know_ what they pay for. I picked the communication challenges new managers face because I have studied this topic extensively before.<p>Five, implement. In my case, I started writing a book, even though I have never written a book before. But I know there are people I can help, so there is a chance that I actually will. My progress so far (shameless plug, accept my apology and please remove it if you consider it inappropriate) <a href="https://www.thenewrole.com/" rel="nofollow">https://www.thenewrole.com/</a><p>This process is a somewhat simplified version of what a marketing expert Amy Hoy talks about. I suggest you check her website <a href="https://stackingthebricks.com/" rel="nofollow">https://stackingthebricks.com/</a> if you are considering starting a side business.<p>Hope this is useful! :-)