A few things I have seen go wrong that are worth naming so you can avoid them.
Do not share your personal prompt library without adapting it. Your frameworks include your personal context, your specific clients, your particular way of working. A shared library needs to be generalised to the team level: clear enough for someone with a different client base and a different working style to use effectively. The structure transfers. The personal details need to be replaced with clear, generic placeholders.
Do not expect everyone to reach the same level of fluency at the same pace. Some team members will be writing sophisticated prompts within a week. Others will take a month to feel comfortable with the basics. Both trajectories are normal and both produce a useful result over time. Set the expectation that everyone engages, not that everyone excels immediately.
Do not skip the verification standards. When you are producing output yourself, the verification habit is yours to manage. When a team is producing output, the verification standards need to be explicit, documented, and non-negotiable. The reputational risk of unverified AI output is the same regardless of which team member produced it. Make the two-tier review a requirement, not a recommendation.
Do not over-systematise too early. Start with one or two workflows, build the shared resources for those workflows, get the team comfortable, and expand from there. Attempting to integrate AI into every business process simultaneously produces resistance and inconsistency. The advisors and agencies who succeed with team integration are the ones who go deep on a few workflows before going wide across many.