Very good advice from Mark on the 'give'...I remember Mark also saying that the makiwara should be hit with the body turned to the side instead of straight on, to protect the joints from the jarring.
I got one of the first sets made of oak that Ihor was selling at one of our camps, about 25 years back.
The trick, as Mark says, is to do this everyday, in addition to the conditioning we do in class with a partner.
The best way for me to insure continuity, was to place it at the bottom of the basement stairs on a table along with a rolling pin.
Since I have all my shoes down the basement, plus the workbench, I find myself going down there at least several times a day.
And I disciplined myself not to come back up the stairs unless I have completed at least 150 taps each shin and each forearm, followed by finger massage and rolling pin.
If you habituate to this, you will have at least 300 taps a day at various intensity, seven days a week...x 365 days for the year...= one hundred eight thousands...
not to shabby to help in your conditioning.