One of the challenges to face jointing is applying firm, steady downward pressure while at the same time pushing the board forward across the knives. The simple shop-made push block, shown below, helps you do this without putting your finger anywhere near the cutterhead.

As you can see above, a hardboard cleat across the back hooks over the end of the workpiece to provide the forward push. And the wide face and canted handle allow you to bear down to keep it flat on the table.