molds need to be very rigid for repeatability, just keep that in mind. wood makes an excellent mold material, but must be finish and completely sealed, then typically gel coated. Plywood/chip board is not of much use unless you’re getting into stuff lich birch or oak ply, which is abusively expensive to use for molds.
For molds I’ll use to make multiple parts, I build from MDF and then fully seal and gel coat/polish prior to use. The larger the mold, the multitude of stiffness required for the part go up dramatically. For one off components, especially complicated chambered parts, a PU foam or polisocyanurate foam plug or mold(sealed of course) is ideal. Once cured, the mold PU can be dissolved leaving the bare carbon component.
If you’re going to make a mold that you plan to use for quite some time, go overbard on the structure and make it storng. And use a tooling gell coat for the final surface. It will be super hard and hold a polish for a long time. The cleaner and stronger the mold, the less prepwork there is in the final product. I use T186 from Fiberglast.
For release agent I use a pva style release film(liquid) with Partall wax. Never have any issue with that combo. There are cheaper one step type agents/waxes that work pretty good. Probably your best bet for small stuff as it take little experience to lay a proper even coat of the premixed stuff.
I like to spend more money on really good resins, epoxies, and prep products as when I do actualy make CF parts for custom race setups it’s usually using expensive 12k triax or 6K5hs weaves. Waste gets REALLY expensive with that product.