Looking great man.
With the length of a plank you go as far as a plank can go in an upward or downward bend not exceding the bend more than the height of the plank .
You have to realise they use trees to cut the plank out of

To work really in scale imagine a large oak tree in your ships scale and cut the planks more or less in the tree its height(count until where the brances star to sprue as tree height)
The preverence goes to a whole lenght of a plank(stronger construction wise)
The point where a plank has to bend up or down more than its own height you have to start with a new plank or a stealer(filler plank),..ussually a stealer though
Try to use as many whole length and unthinned planks as possible though.
Measure the heigth of halfway the hull and see how many planks will fit without thinning them.
Measure the bow and see how much the planks have to be thinned to a point.
Measure the stern and do the same.
The leftover spaces have to be filled up with stealers.
Usually at the stern the planks will be made "wider" by the use of stealers.
At the bow the planks will be made pointier by thinning them.
At the bow use pointy trimmed planks(not thinner than half the height of a plank though) and anywhere where on the hull you have to make a strong bend you can use "stealers"(planks cut in a pointy/triangle manner.)in between planks(see image below)
The "pointy" part of the stealers shouldn't be less than half a plank's height though,or else there isn't enough room for the bold or nail to attache it to the bulkhead,..the same goes for the thinned planks at the bowside.
On a real ship there were far more bulkheads than on your model for sure so imagine at least 4 or 5 more bulkheads between your model's bulkheads and indicate you nails on them.
Go as far as you can go with a full lenght plank as you can go without exceeding the bend more than the height of the plank
Most of the planks should follow the wales (thick dark beams which follow/ indicade the deck location/height).
It is good practice to start attaching the wales first and from them work upwards and downwards with the planking and from the keel up to the lower deck wale.
So,besides the few systems mentioned above there is not really a
View attachment 601706 system,..the only logic is that a plank has to be bolted or nailed to a bulkhead inside the hull and that he length of the planks are kept as long as possible(the less buttjoints on a hull the stronger it will be)