I've posted some similar stuff in the wakesurfing area but here is my press that I made. I got the idea from doing a couple of google searches and then modifying it to my own ideas.
I wanted a concave bottom on mine so I took a 2x12, cut it in half, made the curve on one then outlined it on the other. Took a some old plywood and forced it to fit the curve. Screwing it down to hold it. I also added 2x4's on the back of the press to hold it under compression. I bought two handy panels 1/4" x 24" x48" from home depot -$4 each-. Designed the rough shape of the board but only cut the top deck. Then I outlined the shape on the bottom so I would know where to put the fiberglass resin on. (I didn't use the fiberglass matt, but maybe I should have--of course I'm using this thing for surfing so it should hold.)
Next I sandwiched the panels together, put a screw through each end where my fin hole will be, then put the top half of the press on, added a couple of pipe clamps to hold it tight and let it sit for the night.
In the morning I came out and took the first two pictures. I did a more accurate cut now that both decks were attatched, sanded the edges and painted. (bottom picture)
Now I just need to add some resin to the top, bottom and edges, wait for spring and I'll have my own board, all done for $28 plus some stuff I had laying around the yard. $8 for the wood, $20 for the resin. And for another $30 I can put surfing traction pads on it. Not bad for a wakesurfer price.
The only reason I mention this here is because it would be the same process for a wakeskate.