Sporting events. If the national anthem is played while a JW is in attendance, a JW had better make a scene by sitting down or otherwise, ensure they do not show support for their nation. A JW is not expected to favour any particular team as that would be considered nationalistic.
Greetings to others. Even though not celebrating, when other people offer a holiday greeting such as Merry Christmas, Happy New Year or Season's Greetings, a JW is not to offer the greeting in return.
Trivial Language. Even the most trivial of words can be an issue. A JW cannot refer to the Bulletin Board at the back of the KH as such but must say 'Information Board'. A JW cannot say 'Bless You' or 'Good Luck'.
Words: Words are changed so the old word is not appropriate and a JW using it may be criticised and counseled for doing so. 'Kingdom Ministry' changed to 'Our Kingdom Service' now changed to _____? 'Back Call' changed to 'Return Visit'. 'The Society' changed to 'Organization'. 'The Group' such as where JWs meet for field service changed to 'Rendezvous'. A JW party is called a 'Get Together'. Some word definitions are changed from that commonly recognized (see 'Lie' or 'Lying').
Christianity: JWs are not free to practise Christianity as they understand Jesus specified or as their conscience allows, but must conform to the changing dictates of the self appointed Governing Body.