This is MY opinion and anybody can disagree with it but I think EVERY NAIL TECH MUST be able to trim the cuticle!!!!I don't say you need to do it for every client and every treatment, but when there is plenty of overgrown skin around the nail it definitely doesn't do any favours for the appearence of your hands, or to your health ether... the overgrown skin is dead cells and obviously there is no source of moisture into those cells. One day, dry skin will start to crack and this provides an entry point for any kind of infection. It is our (professional nail technicians') duty to trim the cuticle when it is needed in such a way that we don't damage the client.
If the cuticles are nice and soft - don't cut. Instead, leave them alone as once you trim them, and once the cuticles start to grow even more, you'll have to trim them all the time to keep them in nice condition.
How to trim the cuticle??
You need to make sure you cut them in ONE piece to avoid hangnails after. For me it is easier to do this using cuticle scissors instead of nippers.