I'm by far no expert and I've been reading and searching and constantly learning. Right now the following are my steps. Please correct me if in any way I'm wrong with one of my steps.
1. Cut them down to a couple of inches longer than draw. So you can cut down later if need be.
2. Check the grain.
Horizontal grains(in relations to horizon) will be stiffest area and will go towards the bow. This is fine if you are using glue on plastic nocks. If you are cutting self nocks try to cut across the grains. This helps keep from splitting the shaft. If you go somewhat diagonally you can get the spine further towards the bow and lessen the chance of splitting.(Modified per advice below)
3. Match the spine with a known good arrow by sanding it down until it flexes on a spine tester the same. 2 nails 26” apart works if you have a known good one and try to get the others to flex the same using a two pound weight in the center. Using that method I wouldn’t think that the weight has to be precise.
4. Check the weight of the two and see if they match. Try to sand until you get close. If you make adjustments I adjust lenght. See #7.
5. Find center of the shaft and place it on a pivot. Can be a nail or something. The heavier end make the front.
6. Taper the point and nock. Or cut self nock. Make sure nock on string put’s the spine towards the bow.
7. Tune by standing ten feet away with a target that is level with your arrow. If nock leans to the left the shaft is light for your bow. If it is right it’s too stiff. This can be adjusted by changing point weight. Heavier point lightens the spine. You can also adjust length to get this right for the bow. Shorten to stiffen the spine.
8. If the nock is up in relations to the point then you need to adjust your nocking point lower. Low go up with the nocking point.
9. Fletch away.
Hope all of this is right and look forward to corrections as I'm about to make up another batch.