For many years I’ve used the following trick to plane irregular-shaped objects: Screw a square block to the underside of the piece and then clamp that block in my face vise.
So today I am planing up a seat blank and fetched my little block of wood and two drywall screws. I tossed the block on the underside of the seat blank. The block landed near the front of the seat and I froze for a second.
Usually I screw the block to the dead center of the seat. But I just then realized there’s a better way. Screw the block to the front edge (or back edge) and you can get most of the seat supported by the benchtop.
Chair seats don’t flex much when you plane them. But the extra support is noticeable.
It’s a small detail. But it helps.
If you need some good hand and power tools, check this out.