Memorials for people passed... ideas?

I have seen people use flowers that represent their loved ones and make mention of it in their programs.

My fiance's mom passed away a couple of years ago. She had waited for this day as long as I had. She meant a lot to me and him as well. I wanted her to be able to walk down the isle and honor her in a way that allowed maintain the celebratory tone of the wedding so I plan to do a memory buckle and have it in the front of my bouquet. I have only mentioned it to my fiance's dad so far and will write a little letter to my fiance to have someone deliver it on the morning saying that I know how happy his mom is for us...and let him know she will be there and walking down the isle too with us. Here is a picture of it:

I haven't ordered it yet, but it's on Amazon for 15 bucks.

Photo cufflinks for the hubby with pictures of his mom in them?

I officiated a wedding for a groom who had lost both parents within the past year. As he walked down the aisle, he placed a rose on each chair where they would have sat (front row). Everyone knew what it meant.

Another bride carried the urn of her dad's ashes down the aisle -- so he could walk the aisle with her.

If you have access to the lake itself, maybe you could make little paper sailboats with their names and such on them? Or, since trees are your theme, maybe you could hang the signs in nearby trees, kind of like Christmas ornaments. Or make actual ornaments to hang in the trees. They don't have to be Christmas-y, I've seen some lovely clear glass ones. It'd be easy enough to buy a few and write things on them with paint markers. I hope some of this helps.

We will be doing a special memorial for my Father, and a more general one for the rest who have passed in our families. We're doing a candle for those who have passed and we will have a special photograph of me and my father.

Thank you everyone for the beautiful ideas.

@ Hayley C. I got goosebumps when I read your idea. I think I will do cuff link with his moms picture in them and have them delivered that morning so she can be by his side. We will do other things to remember them all too but that idea Im def doing.