6. Your attorney should welcome you to talking to his past clients.
If the attorney is good they won’t have any problem with allowing you to talk to their past clients? Any attorney that’s proven his worth has a history of satisfied clients that you can speak to.
If your attorney won’t allow you to speak to past clients, you should consider that perhaps there’s a reason for that. If they’ve done a poor job in the past then of course they don’t want you to speak to their clients.