Talking can go a long way toward helping to build trust between you and your partner, but there's nothing like putting the things you learn in these conversations to the test.
While deliberately provoking your partner is not recommended, there will always be situations where you will get the chance to see if the things you hear in your conversations are actually how your partner lives their life.
Hard Times
When things get tough in your relationship, you have a great opportunity to build trust between you and your partner. While you might not appreciate this at the time, knowing that you're working toward true love in a committed relationship can help make difficult circumstances easier.
Depending on how tough things are, you may or may not be able to experience the trust being built while the hard situation is going on. However, if you feel like your partner is supporting you and standing by you while you figure out how to get through whatever is going on, you are probably in the process of building trust with them.
Hard times are also a chance to try commitment on and see how it works with you and your partner. Often, when things are difficult, it would be easier to leave your partner than to stay with them. If you decide to stay together and see how it works out, though, you get the chance to find out whether commitment is something that will work between the two of you. If it seems like a good thing, you will be less likely to feel afraid of a longer term commitment.
Awkward Situations
Everyone has family members who make their lives difficult or friends who are sometimes hard to be around. Once you've talked to your partner about these people, seeing how your partner reacts to them in person will help you build trust and strengthen your relationship.
Things to look for especially include whether or not your partner supports you in hard interactions, how much they tolerate the difficult person, and whether or not they stand up for you if and when that is appropriate. If you feel like your partner was able to stand with you in a hard situation or with a difficult person, you will feel more secure that they will continue to do so throughout the course of your relationship.
Note that it's important that you talk with your partner about your difficulties with a person or a situation before you are in the situation together. It's not fair to lead your partner into a situation that they don't know is going to be a test. Instead, talk beforehand. Tell them why things are difficult and what you think would help you feel better about it. Ask them to be there for you in whatever way they feel like they can, and then see what happens.
While actually testing your relationship can be scary and often means walking through difficulty, it will be worth it when you know you can trust your partner. Then you will feel more confident committing to them, and so will build true love into your relationship.