Sometimes the older Boy Scout handbooks have the best content. The 1959 edition of the handbook has my favorite explanation and definition of the Scout Slogan.
The Scout slogan is “Do a Good Turn Daily.” It is part of the third point of the Scout Law - “A Scout is helpful.” And it is part of your Scout Oath - “… to help other people at all times.”
The slogan does not mean for you to do one Good Turn during the day and then stop. On the contrary, it means to do at least one Good Turn a day. It means looking for opportunities to help and then helping, quietly and without boasting.
When you first become a Scout, it may seem difficult for you to find a daily chance to do a Good Turn. But soon you learn to keep your eyes open and somehow there seems to be an opportunity around every corner. By acting on them, you prove yourself a real Scout.
Some Good Turns are big things; saving a human life at the risk of loosing your own… rescue work in floods… service in hurricane-stricken areas… helping to fight a forest fire… working with your patrol on a conservation project… giving younger boys a good time in Cub Scouting by working as a den chief.
But Good Turns more often are small things, thoughtful things; helping a child cross the street… clearing trash off the highway… picking up broken glass from the street… telephoning the power company to report a live wire.
Remember always that a Good Turn is an extra act of kindness, not just something you do because it is good manners.
To answer the inquiry of a passer-by about an address is not a Good Turn, that is common courtesy.
But to go out of your way to take the traveler to his destination, that is a Good Turn.
Found on page 97 of the 1959 printing of The Boy Scout Handbook