Ok. The big advantages to styrene as a planking material are that it's flexible and it doesn't have any grain, so it's easy to trim to any required shape. The big disadvantage is that it doesn't have any grain, so it doesn't look like wood unless it's given some sort of treatment in the way of paint, texturing, etc. That makes it appropriate for planks (e.g., exterior hull planking) that are going to be painted, but less so for unpainted decks.
I worked from a copy of the plans by Howard I. Chapelle, which I bought from the Smithsonian. I checked them frequently against copies of the original Admiralty drawings; Chapelle was a great man, but he's somewhat infamous for his habit of making changes, some justifiable and some not, when he redrew old plans. But he saved me the trouble of "fairing up" the lines in the Admiralty drawings. (They were made on linen, and stored in rolls for almost two hundred years; those old plans invariably have stretched and/or shrunk.)
I started out by carving the basic hull shape, up to the level of the maindeck, out of laminations of basswood - in two halves, to fit the plywood "keel plate." (I cut the latter out of birch plywood with a scroll saw. It runs up to the level of the underside of the maindeck at the centerline, with notches cut in the top for the deck beams. Amidships the keel plate is cut down to the level of the berthdeck, which I wanted to be visible through the hatches in the waist.) I hollowed out the two halves of the hull to a thickness of about 3/16", then secured them to the keel plate. I built up the bulwarks above the maindeck with basswood strips - the first one being the height of the gunport sills.
I then laid in a stock of Evergreen strip styrene (which, if I remember correctly, had recently come on the market) in the appropriate dimensions. (I'd have to measure to see just what those dimensions were; I think the thickness of the "common plank" was .010," but I'm not sure. The wales, of course, are thicker.) The adhesive was old-fashioned Revell "Type-S" styrene cement in a tube. I wish that stuff was still on the market; I continue to think that tube glue has its uses. In this case it worked quite satisfactorily, softening up the surface of the styrene and soaking into the basswood. (Basswood is far from the best wood for many ship modeling purposes, but it's great for things that have to be glued.) I worked alternately from the wale down and the keel up. I was surprised at how little tapering was needed on the planks between them to get the planking lines to run fair on this particular ship. I expected to need a couple of "stealers" at the stern, but they were in fact unnecessary.
The flexibility of the plastic, and the speed with which the glue dried, were such that no preparation of the planks was necessary and they didn't need to be clamped - even on the sharp curves around the bow. Just holding them in place with finger pressure for a minute or so was enough. I finished up with a little judicious sanding and scraping of the plank edges, but not too much; I wanted the edges of the planks to be faintly visible through the paint. I covered the visible parts of the keel plate - the keel itself, the sterpost, the stem, and the knee of the head - with styrene sheet.
That styrene has now been held to the basswood hull by the Revell cement for just about thirty years, and, contrary to what some of my traditionalist friends predicted, shows no sign of coming loose.
There are several decorative moldings, with rather delicate T-shaped cross-sections, above the gunports. I ground a female version of the cross-section in an old X-acto blade. The height of the molding worked out to .040" (if I remember right), so I clamped a sheet of .040" styrene in a vise and scraped the profile on the edge of it. Then I sliced off a strip of the right thickness and cemented it to the hull.
The last step in the planking process was to plank the insides of the bulwarks. That was easy.
Styrene sheet really came into its own in the construction of the headrail assembly, the quarter galleries, and the transom. That's another story, though, and this post has gone on more than long enough.
If I were building the model again (gawd forbid) I'm not sure whether I'd use this method of planking or not. Since then I've acquired a good stock of nice holly veneer, which I really like; I suspect it would be just about as easy to work with as styrene in this context. I do think, though, that if I were building another model with one of those complicated, basket-shaped headrail assemblies I'd use styrene for that part again.
Hope that helps a little.