Highlighter is very important for some people, some people I know they not only use highlighter for occasions but also on their daily basis and why we highlighter our face because some people don't have fuller looking lips so if you just highlight the central part of your lips. By highlighting this part with a lighter shade of the lipstick you have already put on will make your lips appear poutier and more plump. The area between your crease and your eyebrows. By bringing this out, your eyes will have more depth giving you more space and "drama" to work with. Defining the eyes is important to give you that sophisticated and a put-together look.
Highlighting the top narrow bridge of your nose will make your whole face appear more oval and a bit longer. Plus, this makes your nose look "matangos" so that it looks more, again, 3 dimensional. You want to make your best features come out. I cannot stress this out more.
When wearing a tube or bustier, highlight the center of your neck. This elongates your neck even more making you look slimmer. Bring out your collarbones so that you appear slimmer! There is no other reason and purpose for this. Haha! When you d this step, I recommend using a cream highlighter first before you top it with a highlighting powder.
If you use powder alone, it will just get erased before you even step out of the house. Highlight your chin !!