Organising Music / Genre Tagging

I'm currently having a clear out of all my music and trying to organise it better. At the moment I have all my music saved on my external hard drive. I have cleared the whole of rekordbox until I have been through all my collection.

The problem I have at the moment is coming up with a system where I can organise my music in to easier ways of finding it. Iv read a lot on genre tagging, obviously everyone has there own systems and ways of this but I was wondering if anyone has any tips or advice on the tagging side of things? any would be much appreciated :)

My collection consists of:
House
Deep House
Techno
Tech-House
Minimal
Disco
Nu-Disco