The key to a no make up look is that your skin should look fresh and healthy. So dab a light moisturiser on damp skin, so that it absorbs well and provides the perfect base for your foundation. Avoid a greasy moisturiser as it will leave oil residues.
The nude look should not highlight your skin spots; it should just cover them subtly. So use a light-reflecting concealer to cover any bags. Dab a small amount on dark circles, and blend with your finger carefully.
Choose a foundation that matches your skin tone. The trick to choose the right base is to try it in natural sunlight instead of under the neon lights at beauty counters. Just step out in the sun to see if it matches.
Eye make up:
Anything loud around the eyes or on your eyelid will actually kill the no make up look, so choose a colour like nude or a beige and blend across the lid, going towards the corner of the eyes, to give a clean look.
Use natural transparent beige lip colour. Instead of lip gloss, use matte lipstick. The trick to achieve a natural look is to apply the lipstick and then, pursing your lips together, use a blotting paper to take off any extra colour.