To get the best prices on air travel, try kayak.com. It's a search engine that searches websites (discount sites such as cheaptickets as well as airlines' own websites, except for Southwest).

Make sure you understand the risks when purchasing separate tickets on multiple airlines, especially if you are making connections on the same day. If your inbound flight is delayed and you miss your connecting flight you are considered a no-show and the "missed" airline has no obligation to get you to your destination unless you purchase a new ticket (usually for much more than you'll have saved by purchasing the separate ticket).

Getting better seats on a specific flight without paying "an arm and a leg" is difficult unless you have elite status with that airline's Frequent Flyer program. Depending on the airline "better seating" might be available if you book your flight early but that does't guarantee you'll be paying the "best price" for your ticket.

Generally speaking, lowest pricing and better seats don't belong in the same sentence!

It's extremely difficult to predict airfares to any given destination - they vary from airline to airline, are affected by many different outside forces like time of year, competition, fuel prices, passenger loads, etc. and fluctuate often. The best advice is to monitor airfares to the destinations that interest you and when you see a price that looks go TO YOU book it without too much hesitation as it may not be there "tomorrow". Use websites like Kayak as mentioned by ten thumbs and sign up for "airfare alerts" with the airline(s) of your choice.

Lowest pricing and convenient flight times are often mutually exclusive as well!

My tip:

Visit kayak.com and the individual airline sites at different times of the day and on different dates. Keep it up for a week or two and a some point you will find a fare/route that pleases you. Buy it right then. You have 24 hours to cancel if you change your mind or find something better.

Choose the best seat available when you buythe ticket, but keep checking the seat maps later on. It's possible they'll open up better seats closer to the departure.

I don't know if it is a tip but I was able to get a cheaper biz airfare by travelling on two separate legs and separate airlines instead of a ticket right through. Sydney, Kuala Lumpur, Doha, Cairo.

I would check if the trip is on a codeshare flight as one of the airlines is usually lower. I would book with Canadian Airlines instead of Qantas for a lower fare and each leg was exactly the same. e.g same applies from Sydney to Fiji. It's a codeshare with Qantas and Air Pacific. One is usually cheaper yet you get the same product.

My tip is to take into consideration the cost of your time and the "hassle factor" in addition to ticket price and routing. For example, is it really worth saving $100 if it takes you an extra three or four hours and a change of plane to get where you are going?

There are cheaper days to fly such as Wednesdays and Saturdays. When checking airfare directly with the airlines for a week or two or more, clean your computer cache because it will be saved, therefore, you may not see a change in pricing.

Here's a site that might help http://www.farecompare.com/travel-advice/tips-from-air-travel-insiders/