> If you have a guilty conscience that is going to manifest itself in your body language and mannerisms.
More than once, the customs officer has asked me "you don't look people in the eye, do you?" I just say, "no, I don't." (They're apparently happy with that answer.)
So you can be questioned without having a guilty conscience; I just look down a lot.
Being anxious is something you can work on. Business secrets are perfectly legal to carry across a border. Not wanting the TSA to look at your shit is something I can understand.
I'd basically tell them to fuck off (in a more diplomatic sense) until it reached the point of being either blocked entirely from traveling or detainment. At that point you gotta ask yourself if the juice is worth the squeeze and turn back or play their game.
Also this is more than just an issue with the Trump administration and the TSA... I don't travel to Canada any longer due to the treatment I have received at the border there.
10 years ago I was working in Canada; couple of friends and I (Australian, British and Québécois) decided to go and ski in Montana for a few days. We had a few beers on the way down and stopped just before customs to drop off open cans before we crossed the border. Being 11pm, we were the only people at the crossing. As we circled round they decided something wasn't right (probably justified although not in their jurisdiction) - 4 hours later we were allowed into the US having been fingerprinted and our car searched on a ramp for what I assume was explosives or drugs.
3 days later we returned to the border travelling the other direction - the CBSA officer looked at the cover of all three different nations' passports before saying "I'm sure there's a visa in there somewhere, have a nice day."
Or simply don't have anything to hide. If you have a guilty conscience that is going to manifest itself in your body language and mannerisms.