Most of us keep our foundation as close as our ATM card. And just like crisp cash, we tend to "spend" too much of it. That's the most common problem women make -- putting foundation all over their face when that's very rarely needed. When you get the right shade, and know how and where to use it, you'll find you need very little.

But first, which form do you choose? There are sticks, liquids, creams and powders. If you have normal skin, you're fine with anything. Dry skin is best with a cream or a liquid -- these glide easily over the skin. Oily skin is best with an oil-free liquid but a powder foundation's even better.

I almost always advocate the sheerest coverage possible. I like to see real skin through any foundation. It has life in it -- freckles and little idiosyncrasies are what make you...you. Liquid is the sheerest form of foundation. Powder and dual finish powder are less sheer. And cream can be the heaviest, most opaque of all.

Once you choose what to use, you can still control the amount of coverage. With a cream or liquid, use a damp sponge or -- my favourite tool for applying foundation -- fingertips. I typically squirt some from my favorite pump formula onto the back of my hand and dab on from there. This warms it somewhat, and I don't have to deal with a dispenser while I apply.

To build more coverage, apply in thin layers, using a gentle patting motion so you never pull on the skin. You can also go to super sheer by blending cream or liquid foundations with a bit of moisturizer. With a pressed powder foundation, you can apply wet or dry with a sponge. Wet, you get more coverage. Dry will be more sheer.

It's also good to think ahead to what makeup you plan to apply over your foundation. Cream products are compatible with cream foundations. Powder colors work best over powder foundations.

So, cream blush on top of a dual finish foundation? Bad idea. The powder will "grab" the cream blush and you won't be able to blend it into place. Powder blush on top of a liquid or cream foundation? Also a bad idea, unless you brush loose powder over the foundation to create a compatible surface for your powder blush. Similarly, cream eyeshadows should go over a cream foundation, powder shadows over powder.

A final word about finish: if you've used a cream foundation, your face will be dewy. If you want creams to go matte, add a final dusting of loose powder.

Excerpted from Sonia Kashuk Real Beauty by Sonia Kashuk. Copyright 2003 by Sonia Kashuk. Excerpted by permission of Clarkson Potter, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.