Best workflow after sculpting high poly mesh

Well, I'm old school in that I like to have control of my mesh. The tools that totally automate the process are cool and all, but not really my cup of tea. And I don't even like tea, so a cup of tea is not really my cup of tea. So as a beginner I'd say you stick with good old fashion manual work, so you really get your head around good topology, it's like going to the gym for the brain. So to start I'd say first Blender built in tools and then once you fell you've gone through some proper bootcamp, then tools like RetopoFlow are a super great investment in that is a tool that gives you superpowers while letting you maintain control of your mesh. 

After you have dominion of your mesh, and you can make great topology with loops that flow perfectly, then you wont have any trouble if the asset is going to animation, game asset, 3D printing, etc. Those each require different specifications on the final result, but you'll be able to deliver those if you have focused on building the mesh yourself with proper topology. 

So to summarize, in my opinion, starting doing things manually the old way, with Blender built in stuff, building quad by quad, is what will give you the strongest foundations for everything else.