Putting aside an excel sheet or doing a back of the envelope calculation always helps giving you an idea of how much you need to save for the trip. This will help you cut down unnecessary expenditure of day-to-day nature and gives you a saving goal to look forward to. Depending upon the place to be travelled to and the duration of the stay, you can put down costs for major expenses- like stay, food, sight-seeing, travel. Travel includes flights for your return trip as well as internal transfers and travelling inter-city. Planning an itinerary before this after some basic research and reviews read online is always a good idea.