Anywho...
So I decided to make a little video on how I do my neckbands. I usually always start off with the size of the neckband that a specific pattern calls for. Then, after I pin it onto the shirt, I can tell if I need it to be shorter or a little longer based on how much or little I'm stretching the neckband to fit. Generally the neckband is about 80% of the shirts neck hole.
It's definitely something that will take practice, so don't get discouraged!
After watching the video, please please let me know if I was unclear with anything and need to do some additional explaining on here.
Cheers!