Even with quite light Japanese techniques, it's still possible for a patient go into a vasovagal reaction (normally only the most over-sensitive patients), so I believe avoiding needle shock is a matter of practitioner sensitivity and careful observation of the patient.
For patient recovery, along with standard first aid, I follow Shudo Denmei's recommendations- stop needling, rest, strong hot green tea to sip on (also does wonders for Cold/Weak Middle Jiao - especially Genmai-cha, tea with brown rice added, if no significant recovery in five or ten minutes, some tiny moxa on HT7. I think there is some more (in 'Finding Effective Acupuncture points') but, so far, I've never had to go further than moxa on HT7 to eliminate the needle shock.
I did manage to almost make a patient faint with excessive swift needling once (very superficial in-out needling on the upper back- around the back shu points)- even though the needle wasn't all the way out of the guide tube, so, as I stated before- Practitioner sensitivity and patient observation are key to avoiding needle shock.
Treatment is Diagnosis; Diagnosis is Treatment