Having visited India on many occasions (often for 1-3 months), Nepal a few times, Bhutan twice, Pakistan once and passed through Bangladesh, over a period of more than 30 years, I am in a better position than almost anyone, to give some words of advice had how to conduct oneself as a guest in these countries - albeit that I rapidly passed through cities, en route to the hills and mountains which I feel most comfortable in.
A fundamental truth is that any visitor in another country SHOULD be respectful towards the peoples and customs in the country. In the past, particularly during the days of colonial acquisitions, too many British considered themselves somehow inherently SUPERIOR to the peoples of their colonies, who they believed somehow INFERIOR and their customs PRIMITIVE. Sadly, such sentiments do still exist but THEY DO NOT APPLY TO ME and I challenge them whenever I come across them.
I have a great deal of affection for the peoples of the Indian sub-continent, who in most cases have treated me well, being remarkably forgiving of foreigners lack of understanding or appreciation of the customs of their countries. I am regularly told in the UK that I am "a friend of India" - which I certainly am (despite the criticisms and concerns I raise - just as I have raised concerns, voiced criticisms and challenged schools, churches, an education authority and an MP, over shortcomings in the UK, as there is plenty imperfect here).
Not all my experiences in India have been good - some very bad indeed but mostly I have been TREATED EXTREMELY WELL, WITH GREAT RESPECT. In India, it is the Hindu custom to treat a guest in their homes as the equivalent of a God. I have experienced extraordinary hospitality.
I have been ASHAMED of the way visitors from India or Pakistan and some residents of the UK (including those born here) whose families originate in the Indian sub-continent, are sometimes treated - mindful of how I am almost always treated in India! Once again, when in a position to, I challenge such behaviour. It does not always win me any prizes.
Yes, in big cities and towns in India one has to "be on one's toes", as it is all too easy to be tricked, cheated, robbed or have items stolen. BUT THE SAME APPLIES TO INDIAN VISITORS TO LONDON! And in both India and Nepal, those from rural areas, are often treated badly in the cities, by their "tricky-tricky" countrymen!
Prior to visiting a country for the first time, one should familiarise themselves with local customs. It is correct that the peoples of India are FORGIVING of foreigners not observing all the customs but Western visitors should make more of an effort.
Eating with one's RIGHT hand, makes a lot of sense if you live in the Indian sub-continent (as I explain in my lectures) - it is not in any way 'primitive'. In many respects, Indian people are FAR MORE HYGIENIC, in terms of personal hygiene than us in the West! Though it has to be said that for public hygiene i.e. on the streets, things leave much to be desired but that applied on the streets of London and all over the UK in the past centuries.
We, in the UK and the West as a whole, have PLENTY to learn from the peoples of India and the Himalaya.
RESPECTING LOCAL GODS
It has to be observed that travel by road in the Indian sub-continent is dangerous. The death toll is excessive. Once one reaches the mountains, risks, if anything, increase, with long drops over the edge of hair-pin roads/tracks often of hundreds of metres! So be GRATEFUL when the driver takes a quick break to make an offering to the local Hindu God or Buddha or prays to Allah. You need all the blessings you can muster to survive your journey intact! Just as if you go up into the higher mountains, to trek, photograph flowers (in my case) or climb a peak - be mindful they are the ABODE OF THE GODS.
On my first expedition, I was mindful not to "queer the pitch" for those who followed, meaning that I did not conduct myself in a way which created bad will,
so that anyone following me would be made welcome. The University of Southampton Expeditions to Ladakh in the 1970s and early 1980s, DID Liaise with the local university and the ornithologists did obtain the rings to ring the birds during the ornithological aspects of those expeditions from the body concerned - the Bombay Natural History Society. Just as I liaised with the University of Kashmir during my expeditions to Kashmir in the 1980s.