Just doing crossword puzzles or sudoku is not going to give you the full benefit you want. Just doing crossword puzzles is like going to the gym, doing right bicep curls, and then leaving. Here are some ideas for exercising various parts of the brain:
Word games can stimulate the left front language part of the brain.
Laughter stimulates the right side and can boost creativity.
Learning a musical instrument can boost your temporal lobes and help with memory.
Learning new dance steps and playing table tennis can strengthen your cerebellum, at the back bottom part of your brain and help you with processing speed. Purchase this book and learn more