If you do use a single smart phone, you must have a routine that changes settings permanently or else allow only when you are alone.
On an iPhone, go to settings, notifications. Scroll down to WhatsApp and hit notifications again. Either disable notifications altogether or disable all alerts and sounds, especially 'show on lock screen'. You might want to keep 'badge app icon' which allows you to check quickly to see if you have messages. Then put your whatsapp in a folder so it is less obvious. Discourage all friends and families from contacting you on whatsapp.
Now go back to settings, notifications and see if you have any other programs that you don't want to be bubbling up unexpectedly. Use a numerical lock on your phone, not a swipe. Put any apps and homescreen URL links that you use for punting in a separate folder somewhere less obvious. Set a browser to 'always private' and keep that for punting-only use. If you make notes of a punt, write them in a shorthand code that only you understand.
Under settings, privacy, location services, consider any apps that dont need a record of your location such as Messages or Skype.
If you use Uber, go into the app and delete previous journeys.
Happy punting!