Unfortunately it comes down to trial and error. Some people do have skin that is more sensitive and susceptible to scarring. If done properly, no scarring should occur... Or be very in frequent at worst. The main points to remember are the tech needs to properly insert the needle to the correct depth. Inserting the needle to shallow is usually what causes scarring as the tip of the needle is the hottest part and if not deep enough in to the tissue, it just burn the top outer layer of the skin. Which results in a scar. Also the width of the needle and angle of insertion are important. They have to match the same angle at which the hair is exiting the follicle. Electro via blend is a combination of heat via HF radio waves, and electricity from dc current which causes lye to form in the follicle via a chemical reaction. The heat part can be the most damaging if used by an inexperienced operator. After two weeks of healing, you should see little to no scarring. You can post a pic if you'd like and I'd be able to give you a better answer.
Also Destin diaper rash cream is great for helping your skin to heal and prevent scarring. Tea Tree oil works as well. However proper technique and training are the best prevention against damaging your skin.
