Never forget that they are not your children. You've had your turn now it's theirs.
Never criticize anybody - son, daughter, the in-laws, children. As far as you’re concerned they are perfect.
Offer advice only if it's asked for.
Don't pop around all the time without being asked for.
Try to make visits fun, and think of interesting things to do with the grandchildren.
Remember all birthdays and exam times, and always offer congratulations when they are due.
Always respect the rules of your grandchildren's parents.
If you see that they are in difficulties of any kind, don't criticize offer to help.
Never show favouritism. You may have favourites (grandparents are only human), but keep them to yourself and let nobody guess.
Never undermine the parents.
Never be competitive with other grandparents - it's not grownup and it's pointless.
Try to be useful -- and fun.
Think of a role you can play and nobody else can.
Taken from Things I wish my mother had told me by Lucia Van Der Post