I will start with the most important part of the process: Not being fooled.
There are a lot of people out there that are trying to sell you stuff that is fake.
They have methods to make objects look old.
In fact almost all the "antiques" you can find are not really antiques.
Those are really good copies.
How Far Are You Willing To Go? The more money and time you invest in antique hunting, the better results you will have.
If you find something you like, you can afford it and you can afford to go and check it out personally - don not hesitate.
Ask other people about the seller, do a basic background check about the products he sold before and make sure he's not the only one who is claiming that what he sells is indeed an antique.
Local auctions are usually a lot cheaper then the "Big City" auctions.
Restoring antiques: Sometimes the value of antiques increases after a professional cleaning.
Other times the value is ruined by the removal of the patina or other amateur repairs.
Always ask an expert if you'll need to perform expensive restorations before buying artistic antiques and always ask the seller if any restorations have been made.
Buying an Antique Piece: If it's possible, try to negotiate.
If you are a serious buyer and you're buying an expensive piece, you should be able to negotiate and get it a bit cheaper then you expected.
Usually sellers do think about the fact that a serious customer may want to negotiate and they add an extra amount to the price.
If you see that the seller is not willing to negotiate, don't insist.
He/She might be offended and not sell anything.