Have you ever tried paper tearing on your page?
Alison has used it here to make her page borders, using printed paper. Its worth experimenting with different types of paper and card, they will all behave differently. Some cardstock has a coloured core, and some is surface printed.
If cardstock has a coloured core, you won't see white edges like Alison's page. Printed paper will always have a torn edge, as the ink is sitting on top of the paper from the printing process.
You will find that some tears easier than others. Techniques you could try are:
1. Using a ruler on the paper as you tear to guide you
2. Folding the paper or card gently where you want the tear to happen
3. Wetting the paper along the tear line.
Tearing gives you an informal look to the page, and is very easy to do with no tools at all, so great for beginners or anyone on a budget for buying equipment.