User blog comment:MorganMatthews/Help me make a Ben 10 series/@comment-24922135-20170704000021

Well to start you need an idea to build on. What are your favourite aspects of the franchise and how can you play with those? Maybe a new villain with a unique power/plan? Maybe a new omnitrix with new forms? (that last one alone does not make a great basis for a series, FYI). What a lot of people do/did was take the original series and just replace Ben with a self-insert character. While I don't recommend that as an idea, it is a start for you to then evolve into a new and unique idea.