I give this advice as a newbie as I am NOT an expert, nor a Biologist or Scientist (as accurately stated by another highly Scientific and experienced member).
Please note: The handling of ANY Tarantula should ALWAYS be done with the utmost care, is NEVER recommended and is ALWAYS done at own risk.
Tarantulas have these basic defenses. Run, hide, fight, bite, but not always in that order.
You should always be aware in which order this will take place. Some species will run first, then fight, then bite when cornered. Others will fight, then run, then bite when cornered. Biting specifically stated last in each case because this would almost ALWAYS be a last resort. Depending on the species, you must be prepared to deal with any of these.
Never surprise your spider. They are acutely aware of their environment, therefor, a rule of thumb would be NEVER touch your Tarantula "out of the blue". Always use an extended tong and ALWAYS touch the surrounding webbing or substrate BEFORE attempting to touch the spider. This will ensure that the spider becomes aware of your presence and eliminate the surprise and the initial defence reaction. Then, NEVER approach a spider from the rear. ALWAYS touch the pedipalps first and don't shit yourself if the spider grabs the tong or slaps it with it's legs. THIS IS NORMAL. If it detects that the tong is not food, it will let go. Only now would the spider be "ready" for AN ATTEMPT at handling it.
A fleeing spider is not a happy spider. A spider in a threat pose is not a happy spider. A hiding spider is not a happy spider. If your spider displays any of this behavior, LEAVE IT ALONE.
If you MUST handle your spider, perhaps to rehouse, follow the above rules and ALWAYS work on or close to the ground in an open space. Your lawn or inside a bath tub WITH THE PROP IN PLACE works well.
I have handled H minax, OBT, H lividum almost all Poecilotheria and many other bitches just by respecting and observing their natural body language. If you are aware of its personality, you are prepared for its reaction, then just deal with that.
Use it, don't use it...
Most people are like clouds. The sun comes out when they f*ck off...