I set up central LSC with proxy mines on all entrances, block the door to LSC with a car that has an ignition bomb on it, then go sit on top on the LSC building so it looks like i'm inside. Mug, Merc or bounty the nearest players, sit back and wait. Usually ends in a killing fest when a few players turn up along with the police.
An alternative i do some times is to do the same with the proxy mines, then shoot my way into the LSC, plant stickies and wait.
Spawn in a stock hearse, put an ignition bomb on it and park at the church. Find a high advantage point and wait, once someone drives past (who hasn't got one), they get in and boom. Text a few LOLs and start sniping them.
Look for players flying back and to crates, what till the fly off with one and the drop a proxy on one of the other crates. They come back for it and then boom. Same for landing pads and warehouse blue circles, they land and boom.
Any of these gets me instant salty rage machines coming for me, instant passive mode and follow them around just to keep them salty. They spend more time keeping an eye on me making sure i dont come out of passive for a quick kill than what ever it was they were doing before i started on them.