This is what I've learnt from my almost 2 years of living here in Egypt. Or Mansoura, to be a tad more specific.
1. Do not throw away empty used water bottles, especially the 1.5 litre ones. Instead, refill it with pipe water and put it somewhere, outside the toilet would be a good spot. Because, if you're living in a building where they don't have a motor-generated water pump and your apartments higher than the 4th floor, you don't want to be sitting inside the shower for 15 minutes while getting your housemate to go knock on the landlord's door and tell him to please pump the water. Or even if you have a motor-generated water pump, black outs and insufficient electric current is even worse, because there's nothing anyone can do but pray to God that the power comes back on soon.
2. Do not wear perfumes with very strong fruity note and sit under or anywhere near a tree. I once had on DKNY's Be Delicious and had to run inside a building to save myself from being stung by a bee.
3. Yes heels are sexy and they make you feel confident, but tripping and falling in the middle of the road is not especially when there are people around, which is the case most of the time because the streets here are rarely empty. You don't want to be walking and feeling so sexy and have that look on your face where you know you look good and fall the next minute and rip your pants. Not sexy at all, I tell you. You can save it for dinners, parties and City Stars, though.
4. Always have change in your pocket for beggars. Never, I repeat, never, take out a purse in front of them and fiddle with your money especially when you have a LE 200 and a LE 1 note and when you want to pull out the LE 1 note, you pulled out the LE 200 note too, because they will literally wrestle you for it. Unless you have a friend who is strong enough to push them away and pull you away, you wouldn't want to be in that situation.
5. A ring and an iPod or MP3 player is more of an investment than you can ever imagine. Wear a ring on your finger and plug in your earphones and walk down the street. Saves you from all the boyya boyya and what not. Seriously.