How and where can I find cheaper flights?

The key to purchasing cheap airline tickets is to stay at the destination over a Saturday night. Air fares for the most part, have been priced to the extent where business travelers are charged the most, and those are the people that cannot stay a Saturday night. So anytime that you will not be able to spend a Saturday night at the destination, chances are you're going to be facing a more expensive airfare. If you know the precise dates of your trip, you should always book in advance as many days as you possibly can. With those two items, booking in advance and staying a Saturday night, you're bound to get the best fares and the lowest fares.

Always search flights in stealth mode on your browser. Check Google Flights to get a feel for which airlines fly your chosen route and check their sites. Often, you’ll find a low fare calendar which gives you the dates of the lowest prices for the route you’re looking for. Check often.

Something that has helped me get cheap flights is being open to some wiggle room when it comes to the dates I fly. If you're willing to fly on a weekday or during off hours, you can usually find flights that are cheaper than the flights that are on more in-demand days. I also subscribe to notifications for deals so that when airlines have sales or discounts I can take advantage of them. Some airlines or credit cards also have loyalty or reward programs that you can use to earn points that can help make your flights cheaper.

Not gonna lie, I thought checking flight info in incognito mode was a myth until this exact moment! But I totally second flying Spirit. Seats feel like I'm riding in a rickety roller coaster BUT it saves money. I also always look at Skyscanner for the best prices, but make sure to buy directly from the airline since they usually have the cheapest tickets compared to third-party websites AND they're a lot easier to deal with should anything go wrong, especially if you're booking a connecting flight. Third-party websites will typically not help you if something goes wrong with your flight.

Sometimes I find cheap flights but then it ends up costing more for the extras like bags or seats. Is there a way to know all these ahead of time? Are there airlines that are good to minimize those costs?

I found Southwest A/L was the best to minimize those costs so book flights directly with them.

You can sign up for email alerts from different airlines to get notified when they have sales. You can also try to fly on days when other people are typically not flying. For example, I recently took a flight on Thanksgiving day that was really cheap because most people already want to be at their destination on Thanksgiving, so they're not flying.