For long stretches of my life, I really didn't like myself. By all objective accounts, you'd think that a National Merit Scholar and produced playwright like me would have every reason to think highly of himself, but that's simply never been the case. For no matter how awful or how favorable my circumstances were, a feeling of self-dislike always bubbled under the surface of my mind. It was more visible at some times than others, sure, but it was always there waiting for a sudden disappointment to set it loose.
However, I have recently found some really helpful strategies to help with those feelings. These strategies may or may not be what you'd expect from such a piece of advice, but they are what has helped me, and so I hope that it can help some of you.
I realized a while ago that all intelligent beings have a drive to somehow see themselves in their experience of the world. This is not narcissism (at least as the Narcissus myth is conventionally interpreted), but rather a concrete desire to know that you really exist, that you are not just a subjective phantom, but are real. In ignorance of this desire's existence, many people try to satisfy it by recklessly trying to prove themselves to others. In these cases they look to their actions and others' opinions of them as a mirror in which to see their worth, for they secretly believe that they would stop existing if they stopped their figurative reflection-gazing (Thomas Merton talks about this in his book No Man is an Island). I did this extensively, but I didn't realize that this way of going about it is not only futile, but misses the whole point of the matter.
You see, I have recently found that the best "mirror" to use for this purpose is love. That might sound like a trite cliché, but when you look into the nuances of the idea, you realize that it's quite an effective solution to the problem. As Swedenborg explains, we are all beings of love, and so each person sees herself in what she loves. Love effectively projects one's being onto the outside world, and so as a consequence of this, all a person has to do to effectively see himself is to love somebody else. I learned this only slowly, but I eventually discovered that I could only really get a sense of my true worth by externalizing my concern onto the lives of others.
In that sense, you could say that your heart wants to roam far and wide across your experience of the world, but that if you limit its range to your own experience and concerns, you will stifle it and force it into the captivity of your selfishness. Selfishness, then, amounts to nothing more than an act of self-negation, for by it you force your being to only reside inside your own skin.
However, I will say that serving others often isn't quite enough to fully establish my self-esteem. While it is true that love externalizes your being, it is not the only emotion to do this. Feelings ranging from anger to despair to anxiety are all images of a person's being, and so it is also true that you can see yourself in all of them. And this is the crucial point, for if you don't value those emotions, you neglect valuing yourself.
On this point, I have discovered that it greatly helps my self-esteem to treat every emotion I feel with value. And I do mean every emotion--whether I feel despair, guilt, spiteful anger, or even lust, I have found it incredibly helpful to respect those feelings and the parts of me from which they come. If I don't do this, I find that I don't feel at home in my own skin; indeed, if I don't trust my emotions, how could I ever learn to trust myself?
Practically speaking, I realized that this means respecting both the physical sensations and the fantasies that the emotion causes in me. I talked about the sensations and fantasies of sexual hunger in the post Letters to a Doubter: on Gender and Sexuality, but it is also true that they exist for every emotion. Take a feeling of anger, for instance: though you may resent the intense sensations involved with anger (for me, they are mainly in the chest) and its sudden fantasies of revenge, for me, forcing these manifestations down only makes the problem worse on a long scale. The same works for despair, its feeling of depressed panic, and its fantasies of emotional self-flagellation: if I aggressively fight those feelings, I fight the only part of me I can concretely see while in the midst of that pain.
To reuse an idea from Adam S. Miller's Letters to a Young Mormon, I have found that it is best to experience the emotional sensation or fantasy without either losing yourself in it or forcing it away. I try to just sit with it--letting the emotion and its manifestations come and go without passing judgment. And as I let this activity of emotion simply happen, I get the sense of increased well-being. I feel more solid, more alive, more real. And I guess I shouldn't expect anything else, for I had just respected the only manifestation of myself I could access in such a dark moment.
So, as far as I can tell, self-esteem is a question of truly believing you exist. If you can't see yourself somehow in your experience of the world, I suspect that you will feel somewhat ghostly and unreal. Fixing this can involve letting your love so shine as to illuminate the whole world of your experience, but it also helps to shine upon your entire emotional life the light of value. Doing these things really make one feel embodied and at home in the world, while without them no one can feel at home anywhere.