Practitioner Groups are exactly what they say on the tin; groups of practitioners working or interested in a specific area of work.
Some require you to be working in a certain area, but others will let you join as a student or interested person.
Here's some you may be interested in:
Haldane Society of Socialist Lawyers (£20 for students)
Human Rights Lawyers Association (free for students)
Bar Human Rights Committee (£25 for students and barristers 0 - 5 years call)
Criminal Bar Association (BPTC students only)
Defence Extradition Lawyers Forum (£25 for paralegals, pupils and trainees)
Discrimination Law Association (£15 for students)
Employment Lawyers Association (£45 for trainee lawyers, £20 for employment lawyers in voluntary sector)
Family Law Bar Association (£15 for students)
Housing Law Practitioners Association (free for students)
Immigration Law Practitioners Association (£90 for students)
Inquest (not open to students, £75 for pupil barristers)
Resolution (family law) (free or £35 depending on stage)
If you know of any other relevant groups, then feel free to tell us, so we can spread the word!