Customizing a website's URL

I am trying to develop a system for quickly customizing the URLs of template websites. I am serving clients to rapidly deploy and terminate several template microsites - as they are needed - on the fly. I have developed a series of these template microsites hosted on subdomains in Bluehost. The name servers for these websites are hosted with Cloudflare. As I customize these templates and then activate them, I want each to have a unique domain name. I know that I will have to start by creating a new domain name in Cloudflare. Once I have created this domain name, how would I use it to rename my microsite in an efficient manner? Would a domain redirect work? If so how? Would I have to adjust the records for the website? Would I have to recreate the microsite under the new domain name?