You are planning on going to Brazil because of the FIFA World Cup that has taken place in the country last year but if it is your first time visiting the country, you may want to know the things that you should avoid doing.
It is not a good idea to expose your wealth to the public by wearing extravagant clothes that makes you a delicious target for thieves. Many cities in Brazil like Sao Paulo and Rio de Janeiro have crime rates that are very high. Although most visitors rarely had any incidents with thieves, you have to avoid becoming a target. When you are out from your hotel, carry and wear anything cheap such as your phone and watch. If you insist on carrying your camera, keep it always hidden when they are not in use and be sure to do backups with your photos if you want to keep your memories of the place with you. It is also a wise thing to do to keep small notes together with your inexpensive phone at an event when you become the victim of thievery. If you are bringing larger notes with you keep them at a safe place like your money belt or inside your sock. Keep all your credit cards and passports stored securely at where you are staying, like inside their provided vault.
While in some places exposing too much of your skin is considered vulgar or embarrassing especially when there is that extra belly bulging out of your body but in Brazil, both genders are expected in showing more skin than you are used to be. Take it into your heart that the perception of beach beauties that are fed to you through TV commercials is just a marketing strategy that only occupies the minority of the beachgoers while the majority are all simple mortals with all the imperfections you can imagine. You will get to see all sizes and shapes on the beaches of Brazil and the locals rarely get fussed over with the extra pounds.
Brazil is also filled with social injustice and corruption that most locals are getting vocal for but it is not your place to criticize the country as well. Leave it to the locals to say what they want to say against the government and your job is to focus on the good parts of the country, if you wish to win local friends.