The trekking equipment for Nepal trekking can be different according to season and according to the trekking route you choose. because the temperature is different according to part of Nepal. Normal trekking equipment is as follows.
Boots and spare laces
Fleece or sweater
Trekking trousers (or a long skirt for a woman)
Waterproof jacket /poncho/ umbrella
Underwear (including thermals)
Woolen Hat/ balaclava
Other Essential items
First Aid Kitbag
Sleeping bag(4 seasons +)
Sleeping bag liner
Water bottle (min 1-liter capacity) a thermal better choice
Batteries for camera and torch.
Sun cream (SPF 50) and lip salve
Towel and washing kit
Toilet paper and lighter
Small padlock (to secure kitbag and lodge bedroom)
Notebook and pens
Camera and plenty of drives
Personal snacks and other games equipment
Note: do not bring too many things because porter can carry a maximum of 25 kilos and airlines not allow to bring more than 20 kilos or 15 kilos only for Lukla flights.