Jordan, the keys to a good panel glue up are not starving the joints, and properly jointed edges. Other irregularities like bows can be dealt with. boards they aren't really needed.
Jointing: The face in/face out method of alternating against the jointer fence cancels out any minor discrepancy off 90.
Cauls: IMO cauls are more for keep the joints flush. In the case of panels with several narrow boards, they are needed to for both - flat and even. The reason is 8 joints (16 edges) vs. 2 joints (4 edges) have 4x that chances that even 0.1° of error will multiply. Balanced clamping will keep a panel flat.
Clamps: Pipe clamps produce a force vector that is not parallel to the pipe so panels tend to bow upward. Alternating is critical (but you can get away with it). A 1/4" spacer between the pipe and board will do two things:
- It puts the screw more inline with the panels, which makes the force vector more parallel.
- By preventing the pipe from bowing, it straightens out the force vector. Both these things make a pipe clamp more like a parallel clamp.
Flush joints: On straight boards, alignment aids are not necessary. If they have a slight bow, I'll use biscuits and alternate bow up/bow down do balance out the forces.
I use a combination of increasing clamp pressure a some good whacks with a rubber hammer to bring the joints even. Work from one end to the other. That said, biscuits are a good insurance policy. A cheap alternative to a biscuit jointer is a biscuit router bit.
Post glue up:
- I keep the panels thick, wide and long, so I don't worry about clamps indenting, or boards perfectly even lengthwise.
- That leaves the big issue which is flattening a panel. Many ways to do that hand planes, belt sanders, etc.
- Keep the panel in clamps and cauls until ready to use. After flattening a base coat of sealer can be applied.
- Keep the panel stored in a stable environment, no air movement, no sun, etc. I like to store large panels in a vertical position, as opposed to tying up a horizontal surface.
- Some wood like cherry I keep covered with a blanket. If I can't tie up clamps or for smaller panels, I usually put them in a plastic bag or seal in plastic film.
Panels and tops have a way of "misbehaving" so its all about balance and "holding".