The letter, tissue, flowers are good ideas, yea.
I make up songs. When I was pregnant with my son, and now that we are apart, I sing him songs. It is comforting to me and I want to think telepathically he knows I sing for him. They do not have to make sense. Sometimes, I write the chorus down and it will come back to me another day.
I like to read the letters, that would help me and to possibly place an empty envelope there. I think to follow your heart is best. I took a blanket to sit on the grass and talked to my father. It felt like he was close.
(((hugs)))