Some uses of high-beam:

1. For unlit roads - this could be provincial road, village street, highway with busted street lights, etc. You MAY use high-beam whenever desired EXCEPT:
a. When there is oncoming traffic or car in front of you because you will blind them with this.
b. Be courteous too for pedestrians, masakit sa mata to.

2. As signal (use it even it's Daytime):
a. Flash your high-beam twice quickly if the oncoming car uses high-beam and you are blinded by it.
b. When taking turns in an intersection, you may signal the oncoming traffic to give you chance to go first. They may or may not give you way. Do not force yourself in just because you signalled. Make sure to thank them if they give-way, by honking once. (I turn-off-on my headlights as way of thanking other drivers).
c. On curved roads or streets/intersections where you can't see oncoming traffic - You should signal twice or just keep the high-beam on for them to notice there's a car going the opposite way. Some stupid drivers overtake on curves.

Off-topic tip: In Japan, people are very courteous, they thank other drivers who give way by letting hazzard lights blink twice! (I do this too!)