• Remember the Lazio colours are the colours of your heart. Wear blue, white or sky blue (best of all) whenever possible. When in Rome, this should be achieved as subtly and sneakily as possible. Don’t wear easily-visible scarfs or shirts around the streets. Stick to an unobtrusive scarf pattern (e.g. blue, grey and white) or tiny Lazio emblems. Carry a Lazio pen, keyring, credit card, or wear Lazio undies, small badge, or shirts that just happen to be in a tasteful shade of pale blue. Drink from a Lazio mug; use Lazio cutlery (yes, it exists and I have some). Much good Lazio merchandise can be bought at stalls near the stadium on matchdays. The formerly official shop Lazio Point (via Farini, near Termini) used to have some ok stuff, but since Lazio have ended their relationship with the shop this may change.
• As you may have gathered, Roma fans may give you grief (this was especially bad last season, when they were reigning Serie A champions), so you won’t see too many Lazio fans about. On matchdays they emerge, in groups. You’ll see them on the metro, wearing their scarfs, confident that there’s safety in numbers. Many don’t reveal their colours until within walking distance of the Stadio Olimpico.
• Programme your mobile ring tone to play ‘blue is the colour’. Again, you’ll encounter this fan phenomenon near the stadium but nowhere else, so it might be advisable to re-programme this when in public places, Roma bars etc.
• Learn to cope with the fact that Rome is still full of yellow and red bunting, flags and graffiti from the gigantic scudetto party. Statistical research has demonstrated that there is nowhere in the city you can stand without seeing Roma colours. (Except maybe when they all remove their flags to go and wave them at the stadium.) The team actually play in the city's 'official' colours. Take a trip to the region outside Rome if you want to see biancoceleste support.
• Also get used to the entire traffic system being clogged after a Roma victory as the fans flood the streets on their scooters and in their cars, hooting, waving flags and singing. Try to avoid the centre of Rome after a derby defeat; trying to get home is a very painful experience.

Optional
If you're determined to model yourself on a typical specimen, you might want to consider the following. If you want to remain a sane, decent and tolerant human being, ignore the points below. BUT don't forget some of the crowd responses are vile in the extreme. Be very wary of identifying yourself too closely with the Curva Nord, and don't join in chants you don't understand. (I'd stress here that the bad reputation of Lazio fans is slightly unfair; in my opinion they reflect a more widespread problem in Italian society. The vast majority of Lazio fans despise and have demonstrated their opposition to the racist element.)

• You're stuck with being a Lazio fan but that doesn't mean unqualified support. Lose your temper every time things go wrong - feel free to hurl abuse at your own side. Why waste vitriol on the visitors?
• Hate Roma.
• Cheer anyone who scores against Roma, beats Roma, or overtakes them in the rankings. Follow Roma matches while watching Lazio so you can join in the huge wave of response that ripples around the Stadio Olimpico when something eventful happens whereever Roma are playing.