As an approved driving instructor who sometimes sits in on my learner's driving test, I'm saddened when they fail to pass because they fail to use the POM routine properly, particularly taking effective observations and therefore not moving off safely! You MUST check your blind spots always, and don't just turn your head in robotic fashion, your eyes must register what is around, what is the point of looking if you fail to notice the car reversing out of their driveway towards you?
Finding the biting point
This driving skill is very important, as it affects your confidence and ability to pass the driving test, especially on maneuvers. Make sure that whatever vehicle you are using for the test be it a driving school's car with dual controls or your private customised mini cooper, you can find the biting point repeatedly and with easy, as this another thing that affects how you eventually move off safely.
As the saying goes, 'Practice makes one perfect', spend enough time on the basic driving skills until you can do them without thinking too hard about it, moving off safely and smoothly can be done with a lot of practice so get working on it and your nerves will be less likely to get the better of you during the dsa practical car assessment.