When you think of morality, it's important to see it on two different levels. One is socially acceptable morality, and the other is a deeper level. Socially accepted morality can vary from country to country. For example, in Malaysia it's still legal to have multiple wives. In other countries, one wife is it. Some countries allow you to have alcohol, in other countries none, and so on, those are socially acceptable moralities, laws and guidelines. It's important to follow the laws of a country you are in, otherwise, of course, you end up in jail.
So my advice regarding developing that sort of morality is to be aware that if you don't follow it, then of course Dukkha will come to you in the normal socially acceptable ways. Some people visiting other countries forget this. Which is why, in Thailand, Malaysia, and Singapore for example, there are Westerners in jail because they were smoking dope. They forgot that the socially accepted morality was different.
To go deeper than socially accepted morality though is to develop a basis of Compassion in yourself, so that no matter what the socially acceptable rules are, you are going to look at something deeper, so that you don't want to cause harm.
Morality, in specific, normally refers to what we do with our speech and our actions, but of course that is always preceded by our thoughts. So, to look at our thoughts, look at our speech, look at our actions. Are we doing anything that causes harm? That's one question you can always ask yourself to help develop more morality in your life.
A person who stays married unhappily, not having a good relationship with their wife/husband, and they start dreaming of another woman or man, their thoughts bending in that direction, then if it goes into speech, goes into action, then they are going to cause pain.
When you can look at your thoughts first, and understand that "these thoughts might cause pain", based on your Compassionate Understanding, then your morality will stay more in line on a deeper level. A sideline on that is not to say that everyone should stay in a relationship that is no good, it's just that you should end the relationship first before going and having another one.
When you can look at your thoughts first, and understand that "these thoughts might cause pain", based on your Compassionate Understanding, then your morality will stay more in line on a deeper level. So when we look at morality, my advice on how to develop it is to build the Compassion, not wishing to cause harm with our speech and our actions, which means, of course, looking at our thoughts all the time. Where are they going, which way are they going?