Okay, I'm tell you from the perspective that you are the person who did something wrong and you have lost the trust of someone whom you would like to keep that trust with. So you did something wrong. What do we advise when you've done something wrong? Try to correct it. Try to apologize. Try to make amends. Try to do everything you can to show the other person you are really, really sorry about what you did.
Now, for a lot of people that will be sufficient. The other person will accept our apology. They will semi-trust us again, because they got hurt once, they're not going to fully trust you yet. In the very beginning they may accept your apology but they're probably not going to trust you fully yet. You have to prove that you not only initially show that you're sorry and that you're serious, and that you're apologizing or whatever, but you're going to have to show it again and again and again, day after day after day, that you really mean it.
Otherwise the person will never give you their trust 100%. They'll let you have another chance, but they're still going to have the memory of what you did to them. And in that way, they can't trust you until that memory gets smaller and smaller and smaller, and the memories of how good you are and how kind you are, and how much you care and all that – when those memories get stronger and stronger and they last longer and longer, when they become so strong - then it's possible for them to start trusting you again in more of a full way
One thing you should never expect if you've done something really hurtful to somebody else – don't expect that you can ever get their trust 100% again. That may sound a bit heavy, but if you don't expect it 100%, then you won't be disappointed if the other person doesn't want to give it to you - it's their choice. If you broke the trust, if you did something wrong and broke the trust, then it's up to them to accept you or not, it's not up to you. You can do everything you want to make up for it, but if they're not ready to accept it, then that's their position. You have to accept that that is their position.
Now, ways to regain it, fine, but what about ways to prevent losing trust. One of the biggest ways to prevent losing trust is: don't be selfish. Don't be so centered on yourself that you forget about your loved ones. That you ignore your loved one's needs and necessities. That you take for granted your loved ones. Don't be so selfish, focused on yourself, if you want to prevent losing trust. Show your love to others. Show your caring. Do it regularly. On a regular basis. Do it on a surprise basis. Something we often mention to couples is to find out their partner's favorite candy and to surprise them every once in a while by giving them their favorite candy. A surprise every once in a while. If it's not candy that is their favorite, they maybe cherries. They're so expensive here, right? They're so delicious, right? If you're partner really loves cherries, treat them every once in a while. Do something special for them. The Buddha talked about this in the scripture. Talked about husbands and wives giving to each other. Giving each other presents. Taking care of each other. To prevent being so selfish and to prevent the regret that comes when you've lost somebody's trust.