In most countries locals are genuinely warm toward visitors, especially outside the heavily touristed zones where fatigue can set in. Hospitality is a point of pride across South Asia, the Middle East, Africa, Latin America and Southeast Asia, and travelers are often surprised by invitations to tea or meals from near strangers.
What builds goodwill is remarkably consistent everywhere: learning even five words of the local language, dressing with some awareness of local norms, showing interest in food and culture rather than comparing everything to home, being patient with slower service, and treating staff and vendors politely. Small courtesies like greeting shopkeepers before asking for something make a visible difference.
What causes resentment is equally consistent: loud complaining, haggling aggressively over tiny sums, drunken behavior, treating sacred sites as photo props, and assuming everyone speaks English. In places strained by overtourism, respecting residential neighborhoods and local queues matters extra.
Approach people as a guest rather than a customer and you will find most countries far friendlier than the headlines suggest.