Sagada is paradise thus it is well taken care of. Remember to take nothing but pictures. You're not allowed to pick / get even the small shells / rocks / corals scattered on the shore. Don't throw away your garbage on the sea or actually, anywhere! Except on garbage cans. If you see El Nido, you'll probably be inspired to contribute to the green and clean image of the place. Let's not ruin it. It's one of the few places here in the Philippines that aren't marred by human negligence.
You can also sign up for clean ups on the seashore if you have time. I didn't because our guide said that they just had a cleanup a month before so the private beaches are still clean. But hey, it's fun to help since you also get to enoy the sceneries.
Yes, no skimpy swimsuit on El Nido town's beach. It's really not like Boracay or other places. Normally, when you are on this beach, you wear shorts and shirt over your bikini. You just take this off when you are on your secluded island or beach :)