A personal boundary should be clear enough to follow on an ordinary day.

Rules made in a strong moment tend to be elaborate, conditional and impossible to apply when you are tired. No phone after nine unless something important is happening, no work at weekends except when it is urgent: the exceptions are where the whole thing dissolves. A limit only functions if you can tell, without deliberating, whether you are keeping it.

Take one of yours and rewrite it as a line you could check in two seconds. Make it slightly less ambitious than you want. A modest rule you follow beats a strict one you renegotiate nightly.