1) Stay in Tibet Road when you are in Gangtok!!
2) Enjoy the life in Gangtok the locals are among the most friendly people I've ever met.
3) Ask about the history of Sikkim and you'll find your new best friends.
4) If your a bit low because you haven't eaten meat in India for 4 months then find the butcher in Tibet road, next to him there is a small restaurant where they fry up the best beef Momo's and the staff will drink a beer with you if you stay till late
5) Taste a "Hit Beer"... maybe the best in the world, but is sadly not sold outside Sikkims boarders. Its nice and stong.. i think 8% and is "sadly" only served in 750ml bottles :-)