Do go to the Sambadromo and immerse yourself in the high-camp, Fellini-esque, sensory overload of the official carnival on Sunday or Monday. Splash out on a front-row box, or frisa if you can (around £300). Sector 8 is best because the drum corps from each school backs up a side alley there. Being this close to the intense, hypnotic racket of 300 samba drums is an unforgettable experience.
Do dive into some of the hundreds of blocos—mobile samba parties gyrating down the streets. Kizomba in Lapa, Carmelitas in Santa Teresa and Cordão do Boitatá at Praça XV all come recommended. And do wear fancy dress; if you don’t, you’ll stand out like Russell Brand in a nunnery. In fact, nuns’ outfits are popular...
Do dance at Carnival. Or at least try. Hips in a circular motion, step from side to side, smile. Of course you look stupid, you're a gringo. Deal with it.
Don't go home before dawn, when things get surreal as the survivors wander the streets in the remains of their costumes.
Don't stay in an over-priced beach hotel. Try the Hotel Santa Teresa, in the bohemian village-like bairro of the same name, or a funky pousada in a pacified favela, like Casa Alto Vidigal.
Don't get stuck in the South Zone. Once you've done Ipanema and Leblon beaches and been up the Sugar Loaf, head to central Rio for street life, colonial architecture, and hot samba nights on the Lapa strip.
Do try the bolinho de bacalhau or fried-cod balls, drizzled with chilli oil and washed down with an ice-cold beer (chope) on the pavement at Bar Bracarense in Leblon.
Do visit the Museu da República in the imposing baroque splendour of the Palácio do Catete. Goggle at Brazil’s contemporary history at an exhibition which documents the 1964 military coup. It includes the gun with which President Getúlio Vargas shot himself in this palácio in 1954.
Don't complain about the crowds, the chaos, the mess, the heat or the disorganisation. Brazilians are relentlessly positive. Sing Rio’s praises and you’ll be welcomed.
Don't forget your photo ID. If you do get swept up in the traditional carnival one-night romance and end up in one of Rio’s love motels, you’ll need it.
Do watch your valuables. A light money belt for your wallet and phone, tucked under your shorts or skirt, is a good idea—even cariocas (Rio natives) get robbed at Carnival.
Don't ever, ever argue with a thief, even if the knife or gun he is threatening you with is hidden.
Do remember your manners. Greet women with a kiss on each cheek. Men give each other a handshake and a brotherly pat on the back.
Don't miss the views across the bay from Oscar Niemeyer’s flying-saucer-shaped MAC (Museu de Arte Contemporânea) in Niterói. The ferry ride from Praça XV alone is worth it.
Do snog. Somebody. Anybody. It’s socially acceptable for couples to kiss passionately in public in Brazil. Yes, even at lunchtime.