If you still haven't found your niche, or simply don't know what models are in demand, check CGTrader Analytics, a brand-new tool available to every designer on CGTrader. This tool gives detailed information about the marketplace sales, searches, pricing and available models on keyword level. Have at least 5 uploaded models on CGTrader.
To summarize, this tool is an extremely powerful and detailed, and thus a bit complex, so to learn more we have prepared this page https://www.cgtrader.com/profile/analytics/about , including a short video explaining how to use to the max.