Now, it’s time to start creating and uploading content. Make sure you’re using a high-enough quality camera (most smartphones will work but I’d suggest at least having a tripod so your footage isn’t shaky), but don’t worry about being perfect at first. The beauty of YouTube is that you can continue to test out different content and styles as you find what works for you. Instead, stick to a regular schedule to build up your subscriber base.
The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you.