This simple tutorial is written for Photoshop 7 but the same techniques could be applied in most graphics programmes- All screen shots here are from Photoshop 7.1-

1/ Create a new layer for your torn paper and fill with the colour or patterned fill of your choice .

2/ Select the smudge tool - see below to where you find it - and then select a rough brush - Here I am using a brush from the default brush set called Chalk size 60- the size will depend on the size of the paper and the resolution of your image

3/ Carefully drag out from the edge of your "paper" to form the tears of the mulberry paper - you can repeat the smudging effect as you go till you get the right amount- Dont just drag straight out from the paper - drag at different angles to make it look more realistic

4/ Once you are happy with the torn effect add a small drop shadow and a bevel to give the page some depth - You may like to add a texture as well - this can all be done in the layer styles palette.(Layer- Layer Styles) or click the f button at the bottom of the layers palette)

This is just one of many methods of "tearing paper" and this method looks most like torn hand made or mulberry paper.