I've always been a fan of this song by Fred Rogers.
Not only is it a great song to include in a card to a friend but also a great personal reminder to love yourself just as you are, in the present moment.
It's you I like.
It's not the things you wear.
It's not the way you do your hair,
But it's you I like.
The way you are right now,
the way down deep inside you,
Not the things that hide you
Not your toys--they're just beside you.
But it's you I like.
Every part of you--
Your skin, your eyes, your feelings
Whether old or new.
I hope that you'll remember
Even when you're feeling blue
That it's you I like
~ 1971 Fred Rogers (what a great man!)