About the grain at the ends of boards, special treatment, usage, hiding etc.

The grain at the ends of boards are like a collection of straws and as such can cause problems with a piece. Sometimes it's because they absorb to much stain making them stand out, or is just might be because it is just visually different. Whatever the reason end grain often needs to be considered and treated differently than the other faces of a board and this leads to questions on how.