My Skin-on-frame rules:
1-Relax. You can do this.
2-Very few mishaps cannot be fixed. Ultimately if you screw up, step back for a day to think or ask for help.
Keep it light, flexible and structurally balance.
3-There is no need to be rigid. Your eyes and your hands can do most of the measurement. It is more art than engineering.
4-Avoid hollow hull shapes.
5-Lashing is fun. Stay away from glue except for scarfing. (Even then)
6-Don't get hung up on the supply. I built good boats with wood found in the garbage, nylon string from the hardware store, beeswax and cotton canvas. It lasted for years and only died when I engaged in extremely aggressive destructive testing. You can be as thrifty or as fancy as you choose with only 15 % variance in final product seaworthiness.
Here is a seemingly complex one that I never heard mentioned anywhere else. I might even have personally come up with it. Anyway, here goes...
7-Any straight longitudinal member (stringer), keel or gunwale) bent into the boat structure will flatten the sheer of the boat. (Wow) For example, if you steam bend the gunwale off a small kayak meant to have a lot of rocker. You would then add the ribs and marvel at the beautiful shape of your boat on the saw horse. You then take your straight keel stock and stringers. As you lash them to the ribs, the boat shape will flatten with the straightening action of the newly added straight stock.
Let me know if it does not make sense.