I'm very impressed by your daughter and her sign, whenim64. What a good idea for making customers feel that they know exactly where they are. I go to the hairdresser every 2 months or so as she makes a better job of cutting my fringe than I do. It takes about 10 minutes maximum (including quite a lot of time talking about how her children, whom I know, are getting on) and she has always charged me £1. I never tip, but I do ask regularly if she wouldn't like to increase her charge. In fact we rarely tip; never in restaurants - why should you, when you don't tip the people who actually make the food and what you are paying for is to have it bought, cooked and brought to the table and for someone to wash up. The restaurant should set their prices to cover all that. (In some countries it is customary to leave the change, even just a small amount, and we do that when abroad, but it would probably be regarded as an insult here.) Neither do we tip in hotels, nor the bin men or the postie, although we do give eggs to the best posties from time to time.
Having said that, we do seem to tip in taxis, though I don't know why. In our (small) town, where the waitresses in cafés are likely to be young local girls, I will leave a tip, but not a strict 10%. We also tip the paper boy and so far it's been £5. This year we have a really good one, whom we will tip with pleasure; the last one was a dozy individual who made life quite exciting when you never knew which paper, if any, you were actually going to get. We had him for 2 years and tipped him only once.