I was chatting to my Mum about this tonight and she agrees with those of you who say that friends, family and guests to the house are entirely different to clients, and she advised me not to ask people to remove shoes.
I myself have a massive complex about my feet, nobody ever sees them not even my family(!), I don't own a single pair of sandles and never have, even to the extent where people think I'm mad but I take my own slippers to people's houses and always make sure I have clean socks in my handbag because my worst nightmare would be to find myself in a situation where I had to remove my shoes and expose my feet, it's something I've always had since school. Having a spray tan is such an anxious experience for me as my feet are on show, and I always wear rolled-down socks when having my waxing done. So I wouldn't want to make my clients feel as uncomfortable as I do in these situations!
I don't have a problem with telling my family, but I'm not going to ask clients to remove their shoes. It would be an incredibly awkward way to meet someone for the first time and begin an appointment. In an ideal world the house would be set up differently but I have only ever worked mobile until now so it was never a consideration when we bought the house/carpeted it. The treatment room itself used to be our guest bedroom, and it makes a lovely, private treatment room right at the top of the house but for now the only people who I treat at home are friends and family, and mobile seems to suit my situation best all round for the moment.
Thanks for your replies and opinions - something which has really divided people and it's enabled me to see all sides.
P.S The suggestions of the "take your shoes off" door mat and little wooden signs made me smile, along with the forensic-style plastic shoe covers