How we change what others think, feel, believe and do
Make Them Grateful
Find ways to make them grateful to you.
Show them to the best table you can, while telling them why this is a good place to sit (cool, warm, quiet, light, interesting, etc.). Ask them if this is ok and if they'd prefer somewhere else.
Offer advice on the menu, especially if they seem uncertain. Ask about the sort of things they prefer. It can build trust significantly if you tell them what isn't as nice as other dishes and suggest cheaper options first. You may then say 'If you're looking for something special, this is particularly nice. I know it's more expensive but most people think it's worth it.'
Offer to bring them tasters of food so they can choose what they really like.
Keep an eye on them and look for ways to help, for example if they drop a piece of cutlery, immediately exchange it (for example from a nearby unoccupied table). Offer to call them a taxi if they need one. If they have any complaints, deal with them generously.