The time of year you will be in Nepal will determine the type of clothing you will need.
In winter, December to March, it can get very cold in the Kathmandu Valley, so it is advisable to bring a warm coat (down or polarity is best), long pants or trousers, shirts and t-shirts, thermals, good shoes, scarf, warm hat, gloves and a raincoat (just in case). If you are planning on trekking, bring suitable trekking boots. Runners are not suitable for trekking.
Although it is warm in summer and the rainy months, it is advisable to bring a warm coat (just in case) along with pants, long shorts, skirts, shirts and t-shirts, sandals and shoes. Short shorts and crop tops or revealing clothing are unsuitable for women for cultural reasons.
Basic toiletries are available throughout Nepal with more variety in Kathmandu. Toilet paper can be purchased in larger towns. For women, tampons and sanitary napkins are also available in Kathmandu.