I wouldn't say it was necessary but sometimes it's nice to show the ladies a little extra appreciation. I think it's true the best gift is a tip but i have bought a varied list of gifts that have been genuinely appreciated. I've bought wine, chocolates ,jewellery,lingerie and i even bought something as simple as cheese and crackers to go with a bottle of wine. The cheese was hand made by me. To answer the question when is it best to bring a gift i personally usually keep that for ladies I've known for a while. I wouldn't necessarily bring something on a first visit although i have broken that rule once ot twice.