My Sweetie is stationed in CA (Marines), but our home is in NM, so we don't get to spend a lot of time together right now. But when he comes home, he manages to leave little things for me, so I know he's always thinking of "US".
On one of his return days, I had to work, so I had to leave the house while he was still there (really hard to do). After I left, he ran to the grocery store and bought a bunch of flowers, brought them home, took down EVERY vase we own (I collect crystal), fill each with flowers and spread them through out the house. I came home that night wanting to cry becasue I knew the house was empty, and found the flowers he'd left...pretty awesome.
When we were in high school, he had a habit of removing the pull tabs from his soda cans and giving them to me. Neither of us had a lot of money, so those tabs didn't happen a lot. I kept them all and would thread a string bracelet through them and wear it on my wrist. He does the same thing now with Monster tabs (I still wear some around my neck on a set of his dog tags) and the dove chocolate wrappers with sayings on them (when he finds one he likes)...only he'll leave them in odd places for me to find after he's gone. I've had them drop out of my tea cups, I've found them in my jacket pockets, in the cup holder of my truck, on the edge of the fireplace mantle, under my purse, in my make-up drawer, on my pillow...
He snuck a note into my drawer at work telling me how much he loves me and how much I mean to him...I found it after he'd left. My bldg is secure, I have to escort him in, so I have no idea when he did it...maybe when my boss called me into his office (which is actually joined to mine)...he also made me an "award" out of office supplies and left it on my desk...