Beware of the man who agrees with all that you say: he wants your job!
BEWARE the man who agrees...
Beware the flashy car and the fashionable wife, the penurious misogynist said.
BEWARE OF the flashy car and the fashionable wife...
I know this question has been asked before here
but OP apparently did not find a conclusive answer, and after reading the whole discussion I am still not quite certain when or where to use 'beware of' and when to go with just 'beware.' Can somebody provide a 'rule of thumb' for this usage?