You can grab a product called hurricane spray that is typically used to numb the back of someone's throat and it can help a tiny bit. It's only topical though and so the IV start can still hurt a bit. Try to avoid sensitive areas if the person is extremely pain or needle phobic. Hands, wrist, and sometimes low forearm will hurt more. AC is more just a mental thing, same with bicep. Mostly just talk the person through, worse case if they have to have it and won't hold still, get help to hold and make it quick. Also, make sure they understand that no needle stays in their arm, it's just a flexible plastic tube. So many don't understand this.