Using a highlighter when revising new material is a common practice, but it may be a complete waste of time for you.

What often happens is that by the time you have gone through the material, highlighting as you go, there are so many highlighted areas that it becomes useless when you go back through and start reviewing the material.

What may help is an approach that turns highlighting on its head. It involves highlighting the areas that you don't want/need to focus on. This may be because you already know the material well enough, or it's common sense, or maybe just not that relevant.

The process is simple. Go through the material and highlight the stuff that you don't intend to review any further. This can be done either figuratively, where you don't actually highlight things; you just make a mental note to skip that particular section during subsequent review sessions. Or you could take the literal interpretation and highlight sections which are to be ignored with a grey highlighter.