there are 2 words that helped me really learn...
trial... error...
Even after watching videos, you will have to learn how to do it! A few tips I would give to help making consistent string lengths..
1. Use a jig
2. Be sure you have some type of measurement for your loops or else string length will vary just because you have different size loops.
3. Take good notes!
4. Learn from your mistakes.
When you are trying to make precise strings, you will have to do the same thing, every time. A loop that is 1/4" larger than supposed to be makes your string short of the mark. For your strings to be consistent, you have to be consistent.
Let me know if you have any questions, I will gladly help in any way possible.
3185473756 - text me anytime