I'd say something like this...If you were to write a letter to your younger self, what would you say? Would you give yourself advice? Or maybe a warning?
I think I'd say something like this:
God loves you more than you realize.
His plans for you are greater than you can imagine.
There is no such thing as rabbit trails. Follow God and all His ways will be made known.
Seek Him more than publication.
Trust Him even through the tough stuff.
Believe in the molding process. The goal is to make you more like His Son.