To be really safe you should never even think of not wearing your hi-vis vest when engaging in any activity on an airport, the hi-vis vest is number one priority in my opinion.
You've missed one, however.
As well as
- not booking out
- not wearing hi-ris
- turning off the transponder
if you really don't want people to know what you're up to you mustn't forget to
-
paint a fake reg on your aircraft (just covering up the real one doesn't hack it, that'll look suspicious)
and of course you need to turn off all your phones/iToys ect ect.
And when you've done all that ... you'll be all set up for your drug- or people-smuggling run!