Some brain exercises can be as simple as an intelligent conversation or reading something new. Others can be more involved, like doing crossword puzzles or solving lateral thinking puzzles. Here are some general brain exercises you can do anywhere, followed by a few ideas for exercising specific areas of brain function.
Some Simple Brain Exercises An entertaining brain exercise is to invent things in your mind. You can use many techniques for doing this. It can be as simple as looking at things and asking "How could this be better?" Consider a clock, for example, and you might wonder if it would be better if you didn't have to look at it. Maybe a clock that periodically announced the time and even reminded you of appointments might be useful. Other brain exercises involve puzzle solving. These can range from crossword puzzles to difficult lateral thinking puzzles, but a simpler, fun version of the latter, is the basic riddle. For example, "Why wasn't Bertha put in jail after killing dozens of people?" Because she was a hurricane.
Whether riddles are easy or difficult, they get your mind thinking in new directions, and this is good for getting your mind out of it's "ruts." Inventing jokes is one of the more difficult brain exercises, especially if you haven't done it before. Just take a topic or a word at random, and find a way to make a joke with it. The word "Justice," for example, could become "What's the one place in the world you can find justice?" In the dictionary! If you draw a blank after five or ten minutes, move on to the next word or topic.
Brain Exercises For Specific Areas You may want to work on a particular area of your brainpower. Some of us have trouble with visual imagination, for example. To be architects, we would want to improve that. This can be done by concentrating on scenes in one's mind. Imagine walking through your home, for example, and repeat the process until you can easily "see" everything in each room. For better concentration, practice identifying "mind" irritations. Anything that's going on just below the surface is sapping your ability to concentrate.
Become aware of these things, and you can put them on a list or otherwise dismiss them. More formal meditation practices can help with this, but simple mindfulness exercises may be enough to let your natural powers of concentration function. Simple brain exercises to strengthen your memory can be the repetitive use of any memory techniques. For example, mentally placing a list of items to be remembered at predetermined locations in your house, and seeing them there in an unusual way (think cucumbers dancing in the microwave), is one such technique. Just imagining where you'll see a person next, and calling to them by name in your imagination is a good way to remember names. Get a little wild to develop your creativity.
See things and imagine something absurd, like flying lights. For more than just an exercise in imagination, though, you have to create some sense of the image. For this example, I'm thinking there might be a market for little lights on helium balloons. With a more or less neutral buoyancy for the balloons, a party could be full of colorful, floating, moving lights. Recent research makes it clear that exercising your brain makes it work better. A more active brain has even been shown to postpone or reduce the incidence of age-related decline of mental function. So why not start today with some simple brain exercises?