When you attach a banjo strap it is normally best to attach it to the head tightening brackets. First attach it below the neck on the side closest to the floor around the second bracket down. This will support that neck. On the other side. I attach it one or two brackets below the tailpiece.
Some less expensive aluminum pot banjos or even some of the wood ones have little rings to attach the strap. I don’t recommend those, they are in the wrong spot. The fellow in Korea or China that made it unlikely tried putting a strap on and tried to play. The banjo will flop out of place with no support on the neck. If you are sitting, adjust the strap to give support while sitting, If you are standing a lot, you may have to default to the best setting for that, as the positioning when standing may be more important to you. If you are lucky the same setting will be what you like. Most heavy bluegrass banjos don’t require a strap when sitting as they balance quite well in your lap, the inexpensive light ones though are a bit neck heavy and need a strap.
A banjo strap should be made of leather or have leather tabs to attach to the brackets, not metal clips, the metal will clang against the metal parts of the banjo and could scratch the heel of the neck. Straps with leather tabs
There is a strap called a cradle strap that goes through the head tightening brackets that is quite popular. Cradle Straps are for bluegrass banjos that have a one piece flange, not open back or beginner open back banjos that have attached resonators,
like the Goldtone CC 100R
Here is a picture of how to put a cradle strap on an OB 250
Here is a free video that has a section on how to attach a standard banjo strap
Here is a link to a free video on how to attach a cradle strap on a banjo
I hope this article and video is helpful,
thanks! Ross Nickerson