r := mux.NewRouter()

// Single handler
r.HandleFunc("/form", use(http.HandlerFunc(formHandler), csrf, logging)

// All handlers
http.Handle("/", recovery(r))

// Sub-routers
apiMiddleware := []func(http.Handler) http.Handler{logging, apiAuth, json}
api := router.PathPrefix("/api").SubRouter()
api.Handle("/users", use(usersHandler, apiMiddleware...))

// Middleware chainer
func use(h http.Handler, middleware ...func(http.Handler) http.Handler) http.Handler {
    for _, m := range middleware {
        h = m(h)
    }
    return h
}

// Middleware (just a http.Handler)
func csrf(h http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        // do stuff
        h.ServeHTTP(w, r)
        // do stuff after
    })
}

// Basic handler at the end of it all.
func formHandler(w http.ResponseWriter, r *http.Request) {
      // do stuff
}