I got this highchair when Max was born 6 years ago. I love it because it is sturdy, simple and doesn't have the cheesiness that many high chairs do with the ruffles and animal print. But it is definitely dated, so I thought why not reupholster it (in a sense)? 
I had this fabric handy, I wasn't going to use it for any other projects and it's pretty subdued, just black and white. I cut 2 rectangles, one small one for the seat and one large one for the back. Nothing exact, just enough to wrap around underneath the bottom and back.
I then cut small slits in the fabric so that it would wrap around where the bolts were. When I brought it around the bottom I got a large needle and some quilting thread. I gathered the corners together and sewed them so they were tight and secure. I didn't care that it doesn't look too pretty underneath.
I then bought a yard of clear vinyl overlay for about $2. I did the same thing I did with the fabric but instead of securing it with thread I used a staple gun.
Here is the finished product. It looks great in our dining room and blends in instead of sticking out like a sore thumb. I had to turn the fabric on the back of the chair to make it fit, but I figure I won't notice that, especially when it is covered with spaghetti. :)
