Up On The Roof mission
The easiest and fastest way to finish this mission is to first stab the lone walking guard and have Tiny go behind the wall. Quickly have your spy follow him and shoot a few bullets to bring attention. Shoot every patrol coming (only 2 or 3) and if the spy has lost his disguise, make him put it back on. Make him kill everyone without caring if the dead will be noticed. Have your spy poison or shoot all the guards in the mission and liberate the prisoner. Your sniper will be helpful to kill the patrols at the end where you escape. To do this, distract the large patrol so the sniper won't be seen but will be able to shoot. Shoot 3 of the 4 gunman and then the officer. Have your spy poison the last gunman and do the same again for the other patrol. To do this, it is highly recomended you use 1 bullet at the maximum previously.