You would die if you saw our tree. It probably looks like something Nathan and Allie put together themselves. We don't do any theme except for memories. I try to buy ornaments each year that reflect something special and/or new from that year. Then I also buy ornaments that reflect things the kids or we are interested in so we have a weird mismesh of ornaments. None of them are perfectly spaced or coordinated.
My parents did sort of the same thing and I loved to pull out old ornaments and remember the memories that went with them. Unfortunately for my parents final military move the box with our Christmas ornaments was lost. It was a terrible loss and while my parents had many Hallmark ornaments that were actually worth some $$ that the Army could pay to replace they could not pay to replace the glittered pine cone I made in 1st grade or the ornaments we always had bought for our pets. It has really brought me some comfort to do something similiar in our family and it makes decorating the tree so much fun.
When we were decorating yesterday I just about cried a few times remembering why we bought some ornaments and I think Nathan liked hearing about the ones that involved him.

My tree may not look fantastic to any one else but we love it!