I will - and I've started doing this more and more lately - take someone's unlocked PV that they just leave somewhere and look for a tank or a high rank that I might be enough of a pest to that they use their rocket launcher.
Or I just put it in the shallow water and let the tide come in.
Oh, and my new favorite is to set up a car that blocks much of the road that goes alongside the garage for Tinsel Towers and sticky it. If you live in the cheaper apartment that looks over the garage, you can catch people speeding down from Eclipse with that. I've done it a number of times so far. Requires some patience but not that much. Cheaper than ignition bomb and I've had a number of instances lately where the IB doesn't work - either the car vanishes or in some cases, it has suddenly appeared right next to my garage.
Sometimes I will put a bunch of stickies and drive right up to a low level and go boom, but not close enough to waste them, just an attempt to scare the s--- out of them.
I will use people's PVs as "cover" if they are sitting there when a tank rolls by.
I think the cruelest thing that I've done lately was when I was hiding in Paleto Bay with a bounty on me. Some low level comes up in a helicopter (not even a buzzard) with the intent of getting me. I wreck the helicopter, then proceed to wreck him a few times. I get to tank and then just proceed to go after him again and again and again and again until he stopped and wasn't moving. I think he wasn't AFK as much as it was his way of surrendering. I eventually got bored, but then went back after him a few more times. That I felt bad about.
Other than that....
I have a feeling using my tank from this point forward may be the cruelest thing. lol.