I prefer “1=0 OR 1=1”, because when you delete all conditions you can keep 1=0 out of selection and it decays into a no-op rather than destroying a table:
DELETE FROM table
WHERE 1=0[ OR 1=1
AND age > 21
AND xyz = 'abc']
;
Brackets designate selection bounds before text deletion. The above just safely does nothing after you hit DEL.
Without that you’d have to delete whole [WHERE…], which leaves a very dangerous statement in the code.