A point not covered so far, get an accurate copy of your plans. This will be the one you sacrifice for making parts. If you have several parts of the same shape, make a template from this ply, plastic, etc and us that to trace you parts. With the one per plane parts, just cut out the part from the plan copy and stick it on the balsa or ply and cut the part out. I use the 3M Super 77 spray and just mist the back of the plan and then stick it on the wood. Cut and sand to the outside of the lines and when it is finished, you can then pull the paper off the wood and it will not leave any residual adheasive.

Select all the parts that are of one type wood and thickness and stick down the paper parts to get maximum use from your wood. Make sure the grain runs per the plan. With Lite Ply, the strong direction is usually across the surface grain vs along it. Standard aircraft ply the strong direction is along the grain.

From this point on, you are building a kit. As pointed out before, the big difference is you can select the wood and the hardware.

Go for it. Scratch building kind of gets under your skin. You'll love it.

Don