You'll need to start with a set of cardboard or plastic file dividers. I used these ones from Tesco because I liked the colours and they were very cheap.
Each of the dividers in the pack will yield three Personal-size dividers. The first job is to cut the big dividers down into sizes which are slightly taller or wider than a regular Filofax page. You want your dividers taller than a regular page if you're making top tabs or wider if you're making side tabs. The pictures below illustrate the concept.
Already, we're nearly there. Once you've cut a set of these templates, you can work out the tab positions for each. The easy way to do this is using an adhesive index tab (as pictured below), but you could measure and mark if you prefer.
|Top tab cutting guide|
|Side tab cutting guide|
Once you know where each tab needs to be, you simply cut away the rest of the extra strip, leaving the tab standing proud. You can now punch holes in the divider. Do that a few times and you'll have a quick and easy set of dividers.