My dog, a husky cross, has a mind of his own and does not like to follow commands unless there is something in it for him. This is all the more difficult because he is only sometimes motivated by food. We've been practising NILIF, but we are getting fed up of having to wait for ten minutes while he decides if he is going to 'sit' or not (for example). As for 'come', well, that's why we don't let him off leash.
We always ask him to sit before putting his lead on/taking it off. Yesterday, while we stood waiting at the back door, I suggested to DH that he go outside as if we weren't going to take the dog with us. I stayed in and it was funny to watch as the dog looked very concerned, listened carefully to make sure that he really had gone out of the garage and shut the garage door behind him, and then promptly sat without me having to say another word.
This has done the trick, because now when I ask him to 'sit', he does so almost immediately. But, to show his displeasure, he turns around and sits with his back to me!!