The happiest, most satisfying relationships rest on a foundation of implicit trust. If you want your relationship to be all it can be, both of you must learn how to create this kind of trust. Most couples only think of trust in terms of being sexually faithful, though essential, there’s more to it than just that. 
Stay faithful. If a partner is not loyal, a relationship quickly becomes unworkable. People do recover from an affair but usually need professional help to do it. Make a commitment to be faithful and stick to it. If you’re not happy in the relationship, get counseling and not a part-time lover.
If you’re faithful to someone, it means you’re faithful on all levels. This means physically but also emotionally as well. Some people think it’s okay to establish intimate bonds even though they may just be spending time with another person and nothing else; but it’s really not. It will eventually cause problems in your relationship.
Give your partner space and foster kindness. Trust builds in an atmosphere of security and safety. The cycle of hurting each other, either verbally or physically, and then rejecting the other person, creates a lot of fear which undermines trust. Also trying to control your partner’s every move is another type of mistrust, so make sure you’re not possessively clinging on. That will only push him or her away. 
If your significant other wants to spend time with their friends, try to be okay with that. You can always talk about what’s acceptable behavior and what’s not, though. For instance, if your partner says that he or she wants to go to a dance club with friends and you’re not comfortable with it, then it’s something that you need to talk about both in this instance and for the future so that it doesn’t keep happening again and again.
Love your partner without any ulterior motives. Both of you need to feel sure you are loved for yourself and not for some other reason. That could be your family, your money, your looks or even fear of being alone. Make sure you’re with your significant other for the right reasons.
Make your relationship a top priority. It can be easy to take each other for granted and neglect one another. Try not to give all of your energy and time to other people or activities. Keep your priorities clear. If being in a relationship is important to you, then make sure it stays at the top of your list.
Stay to the end. Misunderstandings, conflict and anger are going to occur. However, make if safe for disagreements and the careful expression of anger to happen without raising a fear of abandonment. You do this by never using the threat of walking out.
Keep your routine. A lot of people believe that mixing things up all the time makes a great relationship. In other words, he or she is always planning something new to surprise the other. Although surprises are nice from time to time, stability and uniformity are far more important in a relationship. Uniformity sounds boring, but you need to be predictable to make things work in the long run. Predictability builds trust.
Be reliable. Trust is just another way of saying you can rely on someone. You trust your partner to do certain things no matter what at all times. This trust builds security in a relationship. Make sure your partner can count on you.
If you say you’re going to be home by 5 p.m., then make sure you are or at least let the other person know if something else comes up. The most important factor here is consistency. If 4 out of 5 times, you never bother calling and just come home as late as you want, then that’s a strong indicator that your needs matter more to you than your partner. A happy, successful relationship is when both parties make an effort at keeping up their end of the bargain.
Mean what you say. Your partner can read your face better than anyone else. If you are lying or trying to hide some true feeling by not quite saying all that is on your mind, he or she will be able to tell. The person might even think you’re cheating. When the person knows he or she can trust whatever comes out of your mouth without hesitation, then you are building an unshakable bond.
Tell the truth. Don’t keep anything hidden, nothing should be privileged from the other. You have to know that sooner or later all things come to light, and the consequences of not being completely truthful will kill the trust and ruin your relationship.
Share how you really feel. Too many people never let their partners know what they need. Don’t let your partner wonder, or try to guess what he or she should do for you. It is essential this happens with both partners. If only one partner is being catered to by the other, there is a chance one will feel smothered or the other might feel neglected. Either scenario is not good.
Say no sometimes. It’s okay to listen to your partner’s needs and try to fulfill them, but sometimes it’s just as valuable to say no. You can’t do everything all the time, and you will actually earn some respect when you refuse to do something once in a while. Taking a stand, and imposing your own will can actually enhance the trust between you.
Have faith in your partner’s capabilities. In other words, if you believe at all that the person is not competent in some of the things he or she does, your trust will not be solid. If this is the case, you need to be up front with him or her on the issues in an honest and loving manner. This will allow you to work through this and keep the trust with each other.
Trust your partner. How can your partner trust you when you don’t trust him or her? Having trust takes two people, and without the other person building trust, too, it’s like a fish without water.
This is where you have the opportunity to practice vulnerability. Trusting another person often comes down to how you feel on the inside. In other words, if you tend to be insecure about things, then this could fall over into your relationship in a negative way. You have every reason to trust until the person actually does something that shows you cannot.
Give the benefit of the doubt. One indicator of trust issues is the tendency to think of the worst case in every possible situation. Just because someone missed your phone call doesn’t mean the person is cheating on you. When you trust your partner, it means you give him or her the benefit of the doubt. Each person deserves a chance to explain her or himself before coming to a conclusion. Only then can it be looked at objectively.
Leave your partner’s phone alone. Do either one of you have passwords on your phone? If so, it could be a sign that you have problems with trust. While privacy is important, it doesn’t mean your phone should be protected like it’s Fort Knox. When there’s real trust, the other person will respect your privacy even if he or she has access to your phone. But the bigger issue, however, is if you feel that the person calling your significant other’s phone is a threat to your relationship, then there are definite trust issues that need to be dealt with.
Allow your partner free reign in life. Often, when there are trust issues, you want to monitor everything the other person does and with whom. It’s easy to feel territorial and feel threatened by everyone. However, trust is about having faith and allowing the other person free reign. When you trust someone else, it also means you trust yourself, which fosters healthier relationships in the long run.
There will always be trials and tribulations in a relationship, but when you face difficulties with an open mind and actively work through the difficulties, the trust in your relationship will grow stronger.
Trust cannot be maintained if you are doing something behind your partner’s back (e.g. cheating). Your partner will find out eventually and the trust will be broken. And once trust is gone, it can never be re-established, there will always be a bit of doubt in place of complete trust.