I don't have a jointer, but I have a thickness planer. In this video I show how I built my version of a jointing sled with a very simple construction, yet absolutely accurate results.
I used 25mm / 1" steel square tubing, a couple scrap MDF boards and self-drilling, self-tapping metal screws.
Why square tubing? Because it's cheap and it's straighter than anything I can make out of wood (in my shop).