Any pointers? That is going to be the hardest achievement I think for me (have everything else except the level 50 achievement). Seems nearly impossible to get without boosting.
I waaaaay overthought this, so I'm glad you asked!
try to set up profiles that'll help you with specific bonuses, focus on one and when you get it swap next time you die. for example:
profile 1 - poison / costume. at match start run to your target as fast as you can with costume enabled (so your pursuer might ignore you if seen) and try to poison them. if you get there before your costume wears off you can get your hidden bonus too. once you get killed...
profile 2 - smoke bomb / morph. head to a high traffic area (like the square in florence) and blend with morph to try to get lure / stun / escape. use the smoke bomb on your target to keep them stationary long enough for a focus bonus
try to keep in your head a checklist of the bonuses under your control: discreet, silent, incognito, acrobatic, aerial, lure, stun, escape, focus, hidden, poison. if you get one of each, that's 11 out of 15.
getting those last 4 is tough though since they require luck or sloppy opponents. alliance is best since the co-op bonuses add-up and it's easier to get one off bonuses like close call or double escape. in wanted you'll usually get at least a poacher and savior bonus leaving 2, so you can try to get midair with a gun or try for a drop kill or grounded. if you do the above in a wanted match you'll often end up in 1st place with 3 pursuers which really makes it difficult if you haven't finished the 11.
see? waaaaaaaaay too much thought. I'm actually a little ashamed. or a lot. whatever.
triple escape I just ran non-stop around manhunt matches and got it on like the 10th round (when my teammates started doing the same thing).
good luck, easily the most frustrating thing I've tried to do in a video game.