All of my layout slots are occupied already. For regular bases, I have my trophy base, gold farming base (interchangeable with elixir farming base), and a dark elixir farming base (different layout).
For war bases, I have my usual one that I've been using ever since TH7 (renovations made of course, but fundamentally still the same), a base that is my converted trophy base to being war-friendly, and an entirely new base that I may test in this upcoming war.