Neurobics help keep your brain active and engaged in the world around you. When your brain is active and engaged, you are able to enhance your ability to learn.
The key is to use at least two senses at once, in a new, novel, and different way. This will help forge new nearual pathways and activate ones that may have gone dormant.
Though we encounter new and difference experiences every day, these things do not always qualify as neural exercises. This is because not everything that is new and different provides enough nerve cell stimulation to activate those new neural pathways. If you normally write with a black ink pen and one day decide to write with a pencil, this is obviously new and different from your old routine, but not a big enough change to recruit the new sensory associations that are important enough to stimulate the circuitry of your brain.
For example, you could try taking a shower with your eyes closed the entire time. This will make you rely on your senses of touch and hearing to get through the shower, thus exposing your brain to a familiar task done in a completely new way.
You could also try brushing your teeth, combing your hair, or even eating, with your non-dominant hand. If you are right- handed, using your left hand to do these common activities will stimulate your brain.
Next time you're standing in the lobby of your office building, check out the map on the wall. Does it have Braille markings corresponding with the printed names of each floor or area? If so, take the time to learn one each day. Using your fingertips to read instead of your eyes will also stimulate your brain and get it moving.
Try eating a meal with family, friends or coworkers in silence. Use only visual cues to communicate with each other. Not only will this serve your neurobics purposes, but it will also help you learn to be more attuned to body language and non-verbal cues from those around you.
While novelty for novelty's sake isn't highly neurobic, you can take a completely different route to work one day, or try public transportation or walking. Get out of your normal environment and go away for the weekend.
Try shopping at a different grocery store. If you usually go to a supermarket, try an outdoor produce stand to get your vegetables. If you usually shop in a mall, try going to a small, locally-owned "Mom and Pop" store for a change.
In summary, changing your routine and engaging different senses to perform your usual tasks will exercise your brain. These activities will forge new neural pathways that will boost your brain's power and performance.
