Let's say you are on a long plane trip and the only book you have is "101 mate-in-one puzzles".   You've already solved ALL of them... what next?   What are some ways to get more mileage from such a book?  

The main excercise that I find myself doing is this ->   Assume that the player who is about to be checkmated has in-fact, one extra move.  Then it becomes a new puzzle:   "What are ALL the things the player can do (if any) to avoid checkmate and which options are more effective?  

Are there other folks who have entertained themselves in this manner?   Do people have other ideas for how to get more of a "chess-workout" from such puzzles?    

Thanks!

Or you could make them into mate in 2 puzzles i.e. the mating player has to play a move which isn't mate but forces mate the next move.

Could be hard(or even impossible) for some puzzles. How do you stop all the 'mate avoiding' replies in just 1 move?

Similarly, you can make it a mate in 3 afterwards, and so on...

Still, you may have to learn a lot.
Also seems to lack concentration.
This time, the game was interrupted in poor physical condition, I apologize.
Also, thank you next time.

 Still, you may have to learn a lot.
Also seems to lack concentration.
This time, the game was interrupted in poor physical condition, I apologize.
Also, thank you next time.