The first thing to do is see what catches your eye. Listen to your instinct. Ideally you would see the work of art in person, but you can do this online as well. Once you've identified an image you're interested in, then ask yourself, why that one? Look at it in comparison to something similar and identify why you find it more appealing. Say you're drawn to a landscape - is that because it’s a snowy landscape or because it has figures in it? Once you have that instinctive response, you need to deconstruct it a little more to see why you're attracted to that work.

Find out as much as you can about the artist who made the work. Check whether these works come up at auction regularly and what prices you should expect. Most estimates are based on past auction records so when artists have a much shorter auction record the cataloguers have a slightly harder time. That always represents an opportunity.

For a lower priced auctions, it's not unusual to find that the works haven't come up much at auction so you need to broaden your search. If we stick with the theme of landscapes, find out what landscapes like this often fetch. Try to seek out the closest type, period and, as basic as this sounds, scale. Sometimes a very large work is hard to sell so a more domestically scaled work will be more expensive.

If you're working with a smaller budget, you aren't going to get the brand names. This is to your advantage. You're looking for what in French is called the petit-maître or if you're working with contemporary it's the emerging artist - someone with no track record. True connoisseurs say it's not the name, it's the object. I know a number of dealers who particularly love buying that anonymous drawing or painting and doing the leg work themselves. They might not be able to come up with a perfect attribution but if they do they’ll discover something really remarkable and that’s where the payoff is - both intellectually and, potentially, financially.

There are cycles of taste. There was a period in the 1990s where everyone was buying art of the 19th century. Right now we’re at a time of a lull so this is a good time to buy work from that period if you’re thinking in broader art market terms.

Make sure you know whether the frame is included - usually it is but sometimes an auction will put on an exhibition frame for the viewing. You might be getting a frame that's of significant value so don't overlook that. Also check measurements because you don’t want to buy something that won’t fit in your house - or to be surprised when something is very small. Especially online it can be deceptive to see works in a reproduction. All this information is in the e-catalogue.

As you accumulate art objects, you learn distinctions between them. The benefit of being a private collector is that even if you have a theme - say you're a collector of 18th century French drawing - you aren’t confined to that. It might be where the emphasis is but it’s not like you’re answering to a board of trustees at a museum, you are an individual. Be open to letting your tastes develop and change. Collections evolve over time.

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Elizabeth Pergam is an art historian with an expertise in the fields of 18th- and 19th-century art and the history of museums, exhibitions, and collecting, with a curatorial focus on works on paper. Her major publications include, The Manchester Art Treasures Exhibition of 1857: Entrepreneurs, Connoisseurs and the Public (2011) and Drawing in the 21st Century: The Politics and Poetics of Contemporary Practice (2015). She has held curatorial and research positions and fellowships at the Huntington Library Art Collection, the National Gallery of Art, The Metropolitan Museum of Art, and the Sterling and Francine Clark Art Institute. She is currently on faculty for the MA Art Business and MA Fine and Decorative Art and Design programs at Sotheby’s Institute of Art-New York.