Create a scratch buffer, with a mode and some locals for take off no zigs there

create-scratch.el

(defvar scratch-buffer-locals '(lexical-binding t)
  "A plist of variables and bindings to apply in a new scratch buffer")

(defvar scratch-buffer-mode-locals '(cperl-mode (cperl-indent-level 4))
  "A plist of modes and the buffer locals to set in a new scratch buffer according to mode")

(defun create-scratch-buffer (&optional mode)
  "Create a new scratch buffer to work in. (could be *scratch* - *scratchX*)"
  (interactive "aMode: ")
  (let ((n 0)
	(effective-mode (if (or (not mode) (eq mode '##)) 'emacs-lisp-mode mode))
        bufname)
    (while (progn
             (setq bufname (concat "*scratch"
                                   (if (= n 0) "" (int-to-string n))
                                   "*"))
             (setq n (1+ n))
             (get-buffer bufname)))
    (switch-to-buffer (get-buffer-create bufname))

    (funcall effective-mode)

    (let ((mode-locals (append scratch-buffer-locals (getf scratch-buffer-mode-locals effective-mode nil))))
      (when mode-locals
	(loop for (k v) on mode-locals by 'cddr
	      do (set (make-local-variable k) v))))))