Forgot to mention the models I have done.
Back when I was in grade school, I made a miniature parade float with an amusement park theme. It had a roller coaster with a car on the track running around the parimeter, with a water fountain in the middle. It was mostly card stock, but I also used tissue paper, popsicle sticks, and some styrofoam.
I've also made a miniature R2-D2, inspired my ones I've seen around the net years ago.
Some of my quick ones were of cars like a Delorean and a Jeep. I used autocad to create the designs. These weren't the most detailed models, but were fun to do.
My latest project is a pirate ship inspired candy dish. But I haven't worked on that in quite a while.
Unfortunately some of my older models are no longer in my possesion, as I gifted them. I may have to dig out my old plans and remake them.