There are so many good suggestions, I'm not sure I can make any new ones. I particularly like from HowlerKarma & indigo.
-- Don't assume that "high potential" = "high achievement."
-- If a child is "bored" this is not a statement against you, personally, and does not call for retaliation.
-- For industrious and energetic bright youngsters, differentiation via more work than classmates MIGHT be appropriate-- but it is rarely so for truly gifted children, and the higher the level of cognitive ability, the LESS appropriate it is to add repetition.
-- Another tip may be to realize that children may develop asynchronously, and to teach a child at his/her level of readiness and ability in each area.
