Since my fiancé and I started dating, I have kept a memory box of an item from all the special moments or favorite memories we have together. I have a dried up rose from the first bouquet of flowers he ever bought me, concert tickets, a receipt from a very special purchase together, a stone with a turtle on it that we got from a resort from one of our favorite vacations together, and the list goes on...
I plan to gift it to him on our wedding day, you can start at any point in your relationship and gift it on a big milestone or anniversary. It such a fun way to remember your best memories together. I bought a nice wooden box from Etsy and engraved it with our initials.