im glad im not the only one who wants people to stay off the roof. It just lowers the points of everyone as once one person gets on the roof his pursuer will as well. Then his pursuer will, then the next, then the next. That out of the way, heres some tips.
-Disguise is key... sometimes. While morph is great for long term stakeouts, if your running away and break your pursuers line of sight, look for a group with your persona. Use disguise and blend into that crowd, they will almost always attack your duplicate rather than you.
-The power of a corner is amazing. So you have someone on your tale, and you dont know what to do? Well turn a sharp corner and wait. Stick close to the wall and ensure your very close to the edge without revealing yourself to your pursuer. Once he darts passed the corner theres a good chance he wont have time to slow down. Basically he'll run right by you, at that moment make sure your close and press B. (or circle for PS3 users I think.) You will usually stun them without a problem. This takes practice, but if your not feeling risky, do the same thing only throw a smoke bomb down right as they clear the corner. A quick slap to the ears will take your pursuer down.
-Avoid being obvious. So the person your hunting takes a sharp turn to the right? Walk on by the corner and keep going to avoid suspicion, then turn back around and walk down it again. If you think there onto you, blend into a talking crowd or sit on a bench. This is something NPC's do often, but Players do rarely. Do not do a B line for your target, be conspicuous for maximum points. You get bonuses for doing it in a crowd.
-Rooftops ruin the game. It turns it from "Assassin's Creed" to "Run Around and Die Creed."
-Eyes behind your head. Always look behind you every once in a while. Try to look for anyon who might be tailing you. If you think someone is onto you, shift your movement, if they follow, either run, or let them get close enough to throw a smoke bomb. Thats only if your feeling like an asshole though.
-Death is just a minor inconvenience. Dont allow your death's to irritate you. Respawning only takes a few seconds, and you dont lost any points for it.
-Chillin, maxin, relaxin all cool. If no one is following you and your target is near, sit on a bench or chat in a crowed, attack him or her once they get close, and you will get plenty of points. Even when you ARE being pursued however, dont get excited, your a smooth assassin.
- Slow the fuck down. This is obvious, but it seems some people just dont get it. When you run you very quickly become noticeable by your target. Remember, whenever you do high profile moves such as running, a large red arrow points at you. Your target may know you are there pursuer before you have even identified them.