Back it with several layers of aluminum foil to help shield against ultrasonic weapons.
Make sure your sign post can be used as a weapon.
Bring a bag containing bandanas soaking in 50% white vinegar for tear gas
Bring milk or other dairy for pepper spray.
Companies like black hills infosec have tons of free stuff. Also all the free tools like nuclei, zap, opencve, and shodan.
Best practice is still best practice. Now companies will just have to spend more money on it.