Prevent licking and chewing
One of the first things you can do to help your dog after neutering is to help it stay away from licking and chewing off the stitches.
Consult your vet about fitting your dog with an Elizabethan collar. These are typical dog safety precautions with a very high success rate. If this option is not doable, ask for an inflatable collar as an alternative.
E-collars should only be used when all other methods have failed since they can be unpleasant and annoying for your dog.
These collars are typically advised for sensitive or delicate dogs since they guarantee that their wound is less likely to get swollen or infected.