I stand by the fact that "tips" has no hidden meaning, since people frequently confuse "insure" and "ensure".
1. to guarantee against loss or harm.
2. to secure indemnity to or on, in case of loss, damage, or death.
3. to issue or procure an insurance policy on or for.
1. to secure or guarantee
2. to make sure or certain
To Ensure Proper Service would make sense, but doesn't work with the word "tips". People always claim, "TIPS means such and such" (for example, the sixth response in this post: http://chowhound.chow.com/topics/552081 ), but I don't think that's the case. TIPS means nothing at all, besides whatever the word's actual etymology is.