I booked my trip to Legazpi on Philippine Airlines. I heard from others that Cebu Pacific's ground handlers take care of your bike, even if they were checked-in bare and not boxed. I wasn't sure with PAL.
I looked for suitcases that my Brommie could fit in, but the biggest I found would still result in the seatpost jutting out of it.
So I decided to go half-way. I won't pack it in a suitcase, but I won't leave it bare either.
I bought bubble wrap and cloth duct tape from Ace Hardware. First, I wrapped the fork with bubblewrap because it might have contact with other parts of the frame when folded.
Then, I wrapped the folding pedal, also with bubble wrap. I took off the two clamps, since I heard that they get lost in transit.
When I got to Legazpi, the bike looked normal. I didn't notice any dents or scratches. So PAL gets an "A" for handling my bike with care.
On my way back to Manila, I took Airphil Express. When I picked my bike from the conveyor belt in Manila I notice there were small holes on the bike cover. I guess they were caused by the bike's folding hinges rubbing against other luggages or steel frames. When I unpacked the wrapping, I noticed some paint chipped off from the edges. So I'm giving Airphil Express and the ground handlers in NAIA III a "D" for treating my bike like a sack of rice.
Lesson is, when transporting your bike, put more padding on the edges. Also, secure a "Fragile" sticker over the bike cover (the "Fragile" sticker the check-in counter put did not stick properly on the cover and would fall off).