With more than 16 years traveling and almost 30 countries, I have managed to put together a couple of techniques to find tickets at a good price.
Without further ado, I explain them now:
Incognito session

Open a new incognito session in your browser. For more security, do not open your email in that session, just enter your favorite search engine pages.
If you have ever looked for tickets, you will know that prices fluctuate significantly from one day to the next, and at least I never buy the first time I look.
For the same reason, I don’t let the wanted person read my data, and so I can freely look at prices (this works for everything, not only for tickets).
Why? What the company does is identify each visitor and their searches to get information and then know what to offer you, what you want to buy, or remind you to finish a purchase.
If you saw tickets one day, the company already knows what you are looking for, therefore the second or third time you look, it could put the price a little more expensive because they know you want to travel!
Flexibility

Flexible dates
This point is key to finding cheap tickets and tourism varies greatly depending on the season: high or low.
If we are lucky enough to choose our vacation dates, we can let the search engine find the cheapest ticket. This is possible with Skyscanner.
This is difficult for people who have a few dates a year to travel. But why not make the holidays coincide with the cheapest ticket?
Would you dare to let the search engine find the cheapest destination?

Use different search engines
Take some time to look at prices. Use different search engines or apps that you can to compare and see everything the market offers.
Every time I want to buy a ticket, in addition to checking my favorite search engines, I check the official airline pages, especially the Low Cost ones, in case they have promotions.
Search engines where I always find good prices are: Kayak, Skyscanner, Kiwi, Turismocity, Jetradar, Hopper, among others.

Buy in advance
I always recommend booking the ticket 3 months in advance. It is the ideal period of time, to find cheap prices and to be sure that the plan is going to be carried out.
Planning a year in advance is possible, but a lot can change in between. From your own plans to flights or hotel reservations.
Low Cost
Many times we have prejudices towards Low Cost services, since they tend to be delayed and are somewhat more uncomfortable.
However, this also occurs with the most expensive and most luxurious airlines. They are also delayed and have problems like any other.
Personally, I always prefer the Low Cost airline when the trip is not too long and I save a lot.

This was my official collection of tips for finding cheap flights.
My best kept secrets
Now, I will give you my best kept secrets. These techniques are proven and you won’t find them anywhere else.
Day by day
If you have ever searched for flights, you will know that prices vary significantly from day to day.
For the same reason, when you quote tickets, give yourself some time and check your preferred travel date, but also explore the prices of trips from at least three days back and three days ahead.
It could be that you find convenient prices and decide to change the date of your trip for a few days.
Thursdays
Wait until Wednesday night and Thursday morning to quote tickets.
Rumor has it that airlines set ticket prices for the week every Thursday and unsold seats could drop in price.
Schedule
The time we see prices also influences the results we find.
To buy cheap flights, it is best to search during the early morning or very late at night. Perhaps as demand falls, algorithms also lower prices.
Extreme adventure

This is only for the brave. Personally, I have never tried it, but there are people who say it is real.
The stories say that some people have come to the airport to ask the airlines if there are tickets to the flights that are about to close, and that it is possible to find flights at ridiculous prices.
Although there is also the chance of not finding anything. Would you dare?