People regularly ask whether an item is "a good investment."

The truth is that buying art "for investment" is a shaky proposition.

One main problem is that art is hard to sell.  You need to send it to auction (where you are at the mercy of bidders, and will shell out anything up to 25% in commission to the auctioneer) give it to a gallery (where it could sit for months or years) or put it on eBay (which is a bargain basement -- which is why we're all here, right?)  Otherwise, it's your garage on a Saturday morning.

Art is not easy to dispose of when you need your money back.

Chances are you will get more than you paid over 5 years.  But if you left that money in a high-yield account, chances are you would have made much more.

And over the long term, art markets fluctuate wildly. Your $50m van Gogh may not even get $30m a few years later, when Picasso and Renoir are all the rage.  The same applies to African art.  Sometimes it's in, sometimes it's out.

Another problem: African tribal art in general is very hard to value. With European artists, we can check an auction track record, compare the size and quality of works and get some idea of what the market will pay for an item.  It's less random.

With African art, mostly anonymous and sold by category, rather than by artist name, valuing a piece is very much up to the individual.

What is the difference between the Chokwe figure that sold at Sotheby's for $50,000 and the similar-looking one on your shelf? Who is to judge the quality of art which was never meant to be beautiful, but rather to speak to the world of the spirits?

Yet the financial consideration is an important one.  We want our art purchases to "perform," and since we usually regard them as luxuries or nonessentials, they are often the first things we sell when we need cash.

So here is some random advice:

• Buy what you want to live with, what makes your heart sing.  That way, if you do sell it some way down the line, it will have repaid you a thousandfold by enriching your life during its sojourn with you.  So if your monetary profit is modest or nonexistent, you will still be infinitely the richer for the experience.

• Don't consider the rarity or obscurity of the piece, whatever the dealer may say (and dealers can be very persuasive in marketing their wares!)  It is far more important to let the piece speak to you.  You have to know that you are going to love it.  If you do, others are more likely to love it too.  Trying to sell a rare but dull or hideous item is a sorry business.

• Don't let the dealer influence you too much -- it's his job to talk a piece up.  If you don't think it's magnificent, don't buy it just because someone else says it is.

• Read books, go to galleries and exhibitions.  The more you know about the subject, the better equipped you will be to make decisions.  Try to understand what factors make a piece of African art great -- the criteria are often very different from those that apply to Western art.

• Think about buying things other than masks and sculptures.  African tribal art expresses itself in many mediums that are undervalued right now -- including basketwork, beadwork, pottery and objects made from ephemeral materials like wire, paper and raffia.  These fabulous things can be picked up amazingly cheaply on eBay, and they express the soul of a continent just as much as the costliest gallery items. If anything is a good investment, it is these pieces.

• And don't ignore bronzes!  Bronze pieces, even modern work from Nigeria and Benin, is of astonishingly high quality.  Although most of it is strictly speaking a modern copy of an ancient form, there is surprisingly little difference between recent work and pieces hundreds of years old.  Bronzes are greatly undervalued right now and their aesthetic impact, once you have them in your home, is electrifying.

• Finally, don't be led by names -- "Chokwe," "Luba," "Dogon," Yaka" -- remember to search for pieces that are unidentified (and even unidentifiable).  Let form and function speak to your soul and bid according to what your heart tells you.  You can pick many bargains by having the confidence to buy what you like.  It doesn't always matter what the label says.

• One final point -- buy from dealers who love what they sell.  You can always tell.