First you must select the wood. In this case, Redwood for the soundboard and East Indian Rosewood for the bodies. Then the wood must be thinned on the thickness sander to the proper thickness for bending sides or for the next step.
The sides must have one perfectly flat edge. I accomplish that by clamping this very large and very old and very sharp plane in the bench vise upside down. A couple of passes over it ant the edge is perfectly straight.
Next, the two pieces of book matched redwood must be joined. The edges are perfected by rubbing them over sandpaper set atop the flat surface of the table saw until you cannot detect light between them. Then they are ready to glue.
And here is my gluing technique. four clamps, a bit of visqueen, a couple of straight boards and a 25 could bag of lead bird shot. Simple but it works perfectly. Tomorrow I join the backs and cut the sound holes in the newly joined soundboards (tops).