Letting it idle on a mild uphill slant on a hot day may trigger blue smoke on next startup.
Letting it idle pretty much level on a hot day may trigger blue smoke on next startup.
I suspect that folks like me too cheap to install a catch can may also get a blue smoke could via that path.
If it bothers you, check your dipstick, and fill marks.
Mine does it roughly once every blue moon... but at 50K miles, I have yet to use one gallon bottle of Pennzoil dino fart full synth as top up between oil changes, so it appears entirely harmless.
I guess you could grab a blanket and try to send smoke signals for the few seconds that it does it.