How do you usually do product validation?

Most of the time, I listen to forums and communities. People talking about something over and over may mean something needs to be done. You can also open multiple discussions to test your idea or gather enough data to validate it.

Creating landing pages, building waitlists, talking to users and then working on MVP once I have 50 people on the waitlist. Done the same for my products https://Flezr.com, Siteoly, MicroSaaSHQ etc.

Build the product landing page and launch waiting list.

I prefer A/B testing to get a good sense of things and get in conversations with my audience. The first option tells me what they like and don't and the second option tells me the why behind it.

I think that customer(incl potential) Interviews are most important: Talking to potential customers directly through interviews can help gather qualitative data about their needs, expectations, and challenges. It can provide deeper insights than surveys and allow for follow-up questions and clarifications. There are different ways to recruit interviewees, such as social media, online communities, or personal networks.

User test/ discussions and expert advice for an exprianced source (almost like mentor) who have years of experiance under their belt

To quickly validate your product/idea you may use tools like Checkmyidea-IA or Venturusai