Layered clothing is the rule for the mountains: base layers, an insulated jacket and a shell cover most treks. Good broken-in boots, a 30–40L daypack, sun protection and a water system matter more than expensive extras. Sleeping bags and down jackets can be rented in Kathmandu.
We share trip-specific packing lists for every itinerary we operate — ask and we will send the right one for your group.