If you are new to the concept of the Makiwara, below is an over view from Wikipedia, which you may find useful.
Have a look at the short video showing Sensei's Michelle and Michael training on the new Makiwara, which is overseen by Chief Instructor Ron Bellwood and see how they both adopt different techniques.
Wikipedia: The Makiwara is used by karate practitioners to practice strikes in much the same way as a boxer uses a heavy bag. The makiwara develops ones' striking ability by letting them experience resistance to punches, kicks and other strikes. A poor punch will bounce off the makiwara if the body is not in a position to support the energy generated by the strike. It also develops targeting, and focus, which is the ability to penetrate the target (i.e., opponent) to varying degrees of force.
The makiwara is very versatile, and can accommodate practice of open/closed hand strikes, kicks, knee strikes and elbow strikes. Okinawan methods emphasize striking from different angles. Most sources recommend a regimen of hitting the makiwara 50-100 times per day, with each hand. It is especially important to train the weaker side of the body as hard as, or harder than the dominant side. It is important to note that one should not use the makiwara so much that it causes them harm. Like all good training, there should be no lasting damage.