How to make your Chams seem legit.

There are many ways you can make your chams seem legit, and easily get off of any suspicions. I'm going to list a quick few, just to get you started.

If they're facing towards you behind the wall you see them, say you saw their gun barrel through the wall.
If you see a sniper, say you noticed the muzzle flash, or you saw them moving.
If killcam is enabled, say you saw them there on killcam.
(This one applies for "Super Bullets + Chams only) If they're close to a wall, say their shoulder was sticking out. Also try to shoot their arm if you want to pull this one off.
Say a team mate spotted them for you.
Say "Everyone camps there, I was just checking if there was someone there."
Carry a Heart-beat Sensor, and whip it out every now and then.
Say "I saw you out of the corner of my screen as I passed."
If you manage to grenade them, say you randomly threw a grenade there.
Claim that you snipe there every now and then.
QQ (That works. Really.)
Mock them.
Don't go overboard with your Chams. People will take notice if your score is 80/14.
Avoid prefireing. It is vital that you see them before you shoot!

Of course there's more, I just can't think of them right now. Most of those are pretty basic, but if you never thought of them, it may come in handy! Come up with your own, and share them below!