I will put my answer in bullet points so that you can just follow them blindly!
Book your flight tickets. 3–4 months prior is enough because flight rates don’t change much. (Plan during the months of May,June or July because those are the driest months. Also the weather is cooler because the seasons are opposite there!)
Plan the places that you want to see. Kuta is comparatively cheap but more commercial and noisy. Stay at nearby Seminyak where the prices are slightly higher but the standard is more. Most foreign tourists (read Australians/Europeans) prefer to stay in Seminyak.
Book a hotel. (preferably near the beach, so that you can go to the beach for a stroll whenever you want). I had stayed at the Ping Hotel Seminyak (5 mins walk to the beach). Budget and good hotel.
Exchange money. Take USD with you. No need to take Indonesian Rupiah because you will have to carry more than 1 crore of Indonesian Rupiah which is not convenient. Instead exchange dollars whenever required. Currency Exchanges are available in every nook and corner in Bali.
Activate international usage of your Credit/Debit Cards.
That’s it. Enjoy your Bali vacations. There is nothing to do for immigration.
You will surely love your stay there. Plan for at least 7–8 days because times flies really fast.
(Originally published by me on Quora: https://www.quora.com/What-is-the-process-to-visit-Bali-from-India