How we change what others think, feel, believe and do
Spend Time Together
Take time to be with the other person. Use that time to make them feel good when they think of you.
For example, you can:
In spending time together, look to find the duration and frequency of encounters that will work best for them. For example you could meet weekly for coffee or find a project they are passionate about and work on this together.
If you are together and engagement seems to be fading, either act to reinvigorate it or excuse yourself and leave. Also watch for their body language that may show they want to be elsewhere. Always leave on a high note, with them wanting more, rather than them wishing you would go.
A person seeking to gain trust of a work colleague keeps an eye on them and when the other person goes for a coffee, the person wanders over to the coffee machine shortly after and engages the target person in casual chat. Later, they offer to help with some work. Only much later do they ask for help that will require trust.
A sales person spends time listening to a customer's problems before getting going with their sales pitch.
There is a saying that 'Familiarity breeds contempt'. While this sometimes does happen, it is far more common that 'Birds of a feather flock together'. We are social creatures and like being with others far more than being alone. Spending time together often leads to understanding the other person more, and when we truly understand them it is much harder to dislike them.
Relationships break down when there is little care between people and where one person takes advantage of the other, perhaps taking them for granted or asking too much of them while giving little in return.
Organisations are 'trust boundaries' and people within them often trust each other more than outsiders. This trust increases further when people work together. Armies work hard to get their troops to bond together, often by putting them in difficult situations with the requirement to achieve goals together. For example, dropping them in wild country and saying 'get everyone home'. The shared experiences that result from this builds a high level of internal team trust.