Versatile Shooting Board
I developed this shooting board a few years ago. It uses the same basic principle as any shooting board in that you lay your plane on its side, ensuring the iron is cutting at 90°. You could make this jig as long as you need, and it does not require a lot of materials.
The cam clamps provide a great deal of hold-down with little effort. Shelf pins act as a fence, making it easy to align a workpiece so that it overhangs the base. The pins also help keep a stack of veneer sheets in alignment. You can remove the pieces, inspect the edges, and then slide the pieces back against the pins if they need more work. You can also offset the shelf pins if you want to create tapered pieces.
Drawing by Jim Richey