You get the feeling from Walt Whitman's Song of Myself that Walt loved himself. Good for him; and he got some fine poetry out of that self-regard.
A more difficult, or at least an as difficult, kind of poem to write is one in which the poet describes satisfaction with herself, or at least self-acceptance.
Anne Finch (1661-1720) seems to have written such a poem, logically titled "On Myself."
On Myself
by Anne Finch
Good Heav'n, I thank thee, since it was designed
I should be framed, but of the weaker kind,
That yet, my Soul, is rescued from the love
Of all those trifles which their passions move.
Pleasure and praise and plenty have with me
But their just value. If allowed they be,
Freely, and thankfully as much I taste,
As will not reason or religion waste.
If they're denied, I on my self can live,
And slight those aids unequal chance does give.
When in the sun, my wings can be displayed.
And, in retirement, I can bless the shade.
This is an intricately original poem. As can often be the case with sonnets from the period, the syntax isn't always easy. To what, for example, does "their" refer to in line four? My guess is that it refers to "other people," not to trifles, for it wouldn't make sense for the trifles to move their own passions.
To some degree, the poem seems to concern a self-restraint that comes easily to the person. She doesn't deny herself things by means of excruciating self-discipline, but if she doesn't experience certain pleasant things, she is content nonetheless. Both reason and religion seem to serve as guides, but she seems to work easily within the guidelines, which do not seem oppressive. She describes herself as "weaker"--meaning what? That she is "of the 'weaker' sex"--a woman? Or that she doesn't have appetites as powerful as those of other people?
The concluding couplet sets itself apart from the rest of the poem; the couplet seems to leap to the image of a winged creature--butterfly? bird?--in sun and shade. But the leap seems to work, reinforcing the sense in which the person is both balanced and content with the balance.