First: Shear – every year if you have llamas and live in the southern USA.
Do not know how or need help please check with your local llama association. In Texas links to folks that shear can be found on the South Central Llama Association website http://www.scla.us/shearing.html.
I have been known to take good scissors to mine late in the summer, to pull off new growth. I have carpal tunnel so for me the electric shears are painful to use but, I can do and do use mine if needed. I do hire a professional to do my entire herd every Spring.
The debate over how much to shear is the question we focus on here. It depends on your planned use of the llama. If you are showing and have fans for your animals in the shade or in a barn. The barrel cut may be what you prefer. Most of my customers use llamas for guard animals. I recommend a fully shorn llama in Texas. This cut gives maximum air flow around the body.