The best recovery is to do the same thing lighter
As you mention, doing the same thing lighter is always good, as is cycling casually home from the gym. Percy Cerutty, Australia’s most famous athletic coach, said that doing the same thing lighter is a good recovery technique.
I run daily, and I always fit in a brisk 5km walk as recovery later in the day or evening. It makes a big difference and combined with warming up before and stretching afterwards helps keep me injury-free.