Specific behaviors depend on you. One man might need to stop being so married to his job and be more engaged and attentive when with his wife, children & friends. Another may need to be more assertive and not coddle those around him. So, the first thing you need to do is list what you think you do well, what you think you don't do so well and lay out priorities of the most important thing you need to change.

Next, you need to be willing to give something up. This is the part that causes people to fail to change. People generally expect they'll be able to change something in their lives and on the back end they'll still be themselves... only better. But it doesn't work that way. How could you, for instance, become a faithful husband if you insist on dating other women as you did as a young man... This is an extreme example, but there is a principle at play here.

Your day is completely filled with routines and behaviors that serve a purpose (mostly to your ego). Even bad habits satisfy your ego in some way. Whatever you decide you want to change is going to find resistance in a pre-existing habit or behavior that will have to die to make room for the new behavior you want. The old behavior will fight because it's self-serving to your ego... or, the part of the ego it serves will seek to re-assert itself in another way. This is the condition that Rover Range is pointing to when he says he suggests improving as a husband by "dying to myself before dying to my spouse". You cannot serve two masters, and if you aren't willing to root out the behaviors and the part of the ego behind behaviors at odds with the change you want to make, you won't succeed. Or, you'll only superficially succeed, but will end up having a hidden side, like the politician or pastor who rails against sin, then hires prostitutes. To succeed you must be willing to kill some parts of yourself and understand that the result is you're not quite going to be the same person you were before.

There's an old Zen story (I think there's numerous versions) in which a professor visits some master in order to learn. Upon meeting, the master pours tea for his visitor. The cup fills, then overflows; yet the master continues pouring tea into the cup, which continues to spill all over the table. Finally, the guest can't stand it and exclaims, "Stop! The cup is full. No more will go in!". The master replies, "Like this cup, you are full of your own opinions. How can I show you Zen unless you first empty your cup?" ... In Christian parlance, consider Jesus' parable of the sower... the Zen story is like the seed sown on stony ground, which might sprout quickly but cannot grow roots and dies. In other words, if you want to change (however big or small that change may be), you have to empty your cup; you have to uproot and kill that part of you (in ego) that would prevent the change you desire from taking root. Only then can you internally change.