This is a rule I’ve generally found useful for interpersonal interactions:
Consider the incentives you’re giving people. Behave in a way that rewards people for giving you things you want and punishes people for harming you, instead of the other way around.
For example, let’s say you want people to email you with your requests, so you can process them all at once and they don’t interrupt you. But when someone calls you on the phone, you handle the request immediately so you can get back to what you were doing. In this case, people who call you on the phone get their request handled faster than people who email you. A better policy would be to firmly inform people who call you that the appropriate way to contact you is through email, and that you will be happy to assist them as soon as they email you.
Or maybe you want a person you love to tell you when your behavior is hurting them, so you can stop. But every time they tell you that, you start crying and apologize a dozen times and beat yourself up for being such a terrible person and they have to spend two or three hours comforting you about the fact that you hurt them. Often, you get mad at them, because if they’re saying you hurt them they must be saying you’re bad, and you’re not bad, and it is very unfair of them to accuse you of being bad. They’re only going to bring up ways that you’re hurting them if it’s worth the cost of spending hours comforting you, and you might end up hurting them in lots of ways you don’t know about. A better approach would be to thank them for telling you and say that you’ll think about it, then do your processing with someone else where they can’t see it.
Or maybe you want your romantic partner to spend lots of time with you. But when they’re with you, you spend all of your time talking about how much you miss them when they’re gone, how jealous you are of all the time they spend with other people, how they have a moral obligation to spend more time with you than they’re currently spending, how miserable you are, and how much them not spending more time with you is ruining your entire life. A better approach would be to talk with them about their day.
Or maybe you would prefer that your child not have tantrums. But when they ask nicely for a cookie, you never give them a cookie. When they throw a tantrum, you give them a cookie every time in order to get them to shut up. A better approach would be to give them a cookie sometimes when they ask nicely for it and never give a cookie to a tantruming child.
In general, you should put yourself into other people’s shoes and figure out what’s the best way for them to get what they want, whether it’s a cookie, a pleasant afternoon, or a speedily fulfilled request. Some people are going to do the thing you want them to do, out of altruism or a desire to follow the rules or because they care about you. But lots of people are going to do the thing that helps them reach their own goals the best. So you’re more likely to get the things you want if getting you the things you want helps other people get the things they want.
This seems like a really simple rule but I think a lot of relationships would be improved by putting it into practice.