Can you make it part of your service conditions that they wear a mask you provide at the cost of £1? Be brutally honest if necessary and say that clients have been arriving in unsuitable masks so an acceptable one will now be provided.
Don't turn the dryer off for conversation, pretend you didn't hear, don’t make eye contact and look intent on your work. They'll stop talking
I'm assuming you're warning everyone that their service may be more expensive due to the extra work, time and products, do it by message before if you struggle with face to face. Something alongbthe lines of 'remember I'm contactless payments only at the momoment, your colour/cut/whatever will be £××, looking forward to seeing you' - they can get their heads around it before they come