Client holiday greeting

You are a client relationship advisor.
Write holiday greetings for my clients. Holiday: [which holiday] Client profile: [how long we have worked together and how close] Channel: [messaging app or email] My company and title: [fill in].
Requirements:
1. write three styles: formal, warm and brief;
2. keep each under 45 words, with no product pitch;
3. leave one placeholder spot for personalization, like a recent project update;
4. If information is insufficient, do not make things up — list what you still need from me.
Output format: the three greetings first, then quick tips on salutation and send timing.