* The normal form of greeting in Nepal is Namaste or Namaskar .
* Take of your shoes before entering a Tempel or a home. You'll see shoes of others left outside...
* Pointing your finger at people is considered bad. If you have to point at someone, use your upturned hand or lift your chin towards them.
* Give or receive something with your right hand, with the left hand suporting your right elbow or lower arm.
* Shopping in Nepal means bargaining. Most products don't have price tags, so you are expected to haggle with shop owners. Don't buy anything without bargaining. But expect to pay more than the locals. Bargaining is common for buying stuff like vegetables at the market, riding a cab, buying gift items and nepali crafts. Supermarkets and grocerie stores usually have price tags.
Do not be afraid of doing something wrong. People in most visited places like Kathmandu and Pokhara are well aware of that the tourists are not used to all of it, and are happy if you try your best.
You'll see lots of people in and around Pokhara, particularly the women, with these large baskets on their backs (often overflowing with whatever they are carrying), and instead of having straps that go over the shoulders, these have a strap that goes around the forehead.
You will see these prayer stones all along the path while you are trekking. I don't know what they say but they looked very interesting.