How we change what others think, feel, believe and do
Start by taking the order. The customer may know what they want, but they may also appreciate suggestions. Suggest something to go with their food, and typically from the middle of the wine list. You can trade them up by noting that a slightly more expensive wine is 'particularly nice'.
Show them the bottle of wine before you open it. Open it deftly in front of them, removing any bits of cork or cover with a clean cloth (not your finger!).
If it is the local tradition, pour a little for them to taste. Again with tradition as appropriate, start with the ladies. Never lean across a person to pour wine unless it is forced by a crammed-in table.
Traditionally, a person should not have to touch the bottle of wine and you should fill their glasses for them as the glass becomes mostly empty. Be careful, however, as some people do not like this and prefer to serve themselves. Also be sensitive to drivers who only want a small amount.
Whether or not you pick up the glass to fill it again is a matter of debate. Find what works where you are and follow your experience.
Serve other drinks with equal aplomb. Make the beer foaming and add little umbrellas to cocktails as appropriate.
And when people get drunk, manage this too. Be careful about fulfilling orders for more drinks when they may be getting loud and out of control. Consult the restaurant manager as appropriate.
If you are lucky, you will work in a restaurant where the wine waiter is called a sommelier and is tipped separately. Maybe alternatively you will get a cut of the tips, perhaps proportionate to the wine or drinks bill.
Do know what corked wine is -- it is where the cork has reacted with the wine, not where a bit of cork is floating in the glass. With the large number number of synthetic corks these days and the care that is taken, there is little chance of the wine being corked. It also means that letting them taste a bit has little real meaning.
When you are pouring the wine, there is a better chance that they will get through more wine, making the bill higher and your tip higher too.