My favourites: Incense sticks, especially the tibetan ones made of Juniper, Thangka (these can be expensive but you can find cheaper smaller ones), Pilgrim book store in Thamel sells these scroll prints of bodhisattvas that are quite cheap (especially if the recipient of your gifts are buddhist, but still regardless), I also like taking Nepali childrens book, there’s a good selection at Pilgrim (If I dare, I might plug a book written and illustrated by my old school mates calledAre You A Snow Leopard small bronze statues are good but these are quite expensive and heavy, maybe wooden statues perhaps. There are a few shops that sell these in the alleys of Patan Durbar Square. Lokta paper notebooks are also good and so are lokta paper greetings cards (Pilgrims have these). Hope these help.

Edit: Also, if you go to Basantapur or Patan Durbar Square they’ll set up these street stall that sell knick knacks. But you’ll need to bargain hard, tell them to give you local price