Here is a simple to use technique that makes a huge difference, its called emboss resist. Here is a youtube clip that demonstrates how this technique is done. I love using this technique not only because its easy to use, but also because it looks different every time you do it and, and you can achieve a great outcome every time.
For the first card I have embossed with white embossing powder and used silver for the second one. The colour combo I have used here is Powder Pink and Tranquil Tide, with a touch of Very Vanilla. I brushed over the embossed image very lightly to give it a softer look. Also, I didn't use watercolour paper and so didn't want to damage the paper with too much water colour. Just enough to make the embossed image to pop out. Particularly like how in the first card is a combination of stamp and punched out daisy and an embossed daisy, a slightly different take on it, haven't seen it done yet.