Well, just don't set off any red flags, like shooting people right around the corner or pre-firing before you even see them directly. Also, Hacking is a slippery road. Chamming leads to more obvious things; just try not to go overkill.
I just used the hack today, I don't prefire, I wait until the person shows up, and I follow him, for example, if this guy is coming up behind me, ill just go the other way to kill him, and for sniping, I get headshots too often, and knowing that people are coming up the stairs.
Im a MAJ 5 and ive been hacking for soooooo long, there is a slim chance of being cuaght, just dont opk, even semi opk...use telekills only is u have too. I only use chams and no spread, no reload, no sway. thats really all u need.
like said before, dont set off red flags, and make sure ur fireteam combo isnt like 500, lol.