Yes, I do. If I can get a radar service, I do so.
Otherwise, it's a big sky. Avoid honeypots (the overhead of VORs, for example) and avoid altitudes that are a round multiple of 500.
I've had some scares in CAVOK day VFR - sometimes my fault for not looking out hard enough, and sometimes sheer volume of stuff about on a nice clear day.
IFR in the open FIR, with radar service, it's rare for there to be anything else in the cloud with you.
Freezing level permitting, I sometimes prefer to be in cloud than below it, precisely to avoid the lemmings.
Timothy had some statistics about the number of air-to-air collisions in IMC in the open FIR. I think it was "zero since records began" or something like that.