“Be nice to everyone you meet...but always have a plan to kill them.”
“... have a smile for everyone you meet and a plan to kill them.”
“Have a smile on your face for everyone you meet, and a plan to kill them.”
“Be professional, be polite, but have a plan to kill everyone you meet.”
“A lot of people seem nice when you first meet them. Then later you find out that they are evil villains who plan to take over the world.”
“Encourage everyone you meet with a smile or compliment. Make them feel better when you leave their presence and they will always be glad to see you coming.”