1. Shop around! Call SEVERAL airlines, train stations, etc. Special rates and discounts are often available, particularly if traveling during off-season. If possible, reserve a year in advance and pay early for the special rates. (This may mean a no-frills flight, however.)
2. If it's not necessary, don't stay at the name hotels. (Unless someone else is paying for it!) There are plenty of bed-and-breakfast inns and guest homes that's reasonably priced and have local atmosphere. (This may not be everyone's cup of tea, though.)
3. When putting together your wardrobe, it saves time to pack several basic, comfortable outfits that's mostly solid-colored and interchangeable. And bring comfortable shoes! (Not only for walking, but the stress of being someplace else is reduced a bit, I believe.)
4. If you know that your time is limited, determine in advance what business and sightseeing is absolutely essential and do those first. (Prepare a list of must-sees and contacts.)
5. Take the bus round-trip, if you can stand it and have the time. If the location's close enough, car travel's better.
6. Get a clear, easy-to-read map.
7. Prices are much cheaper if you avoid the swanky downtown shops; Seek out the bargain markets.
8. If a certain site requires two or more means of public transportation to get there, watch out. It may take half a day of coming and going! And your mood WILL be affected. If in doubt about the access to a place, consider a car (riding with another visitor, taxi, renting or leasing an auto) or special tour bus.
9. Avoid most of the food in airports. Unless you have money to waste, they're extremely overpriced, particularly in the major cities.
10. If you're able to, try to arrive at your destination at least an hour early; this'll give you time to relax, freshen up, and get acclimated to your temporary "home." Also, when returning, try to leave THE DAY BEFORE you're due back at work, are scheduled for an appointment, etc.
11. For inexpensive eating throughout your trip, there are several options: if you're able to, you can bring one or a few made-at-home bag lunches, look for and seek out food cart vendors, or stay at a hotel that offers kitchenettes.