Dear [Name],

I am writing to express my sincere gratitude for [reason for thanking]. Your [kindness/generosity/support] has made a significant impact on my life and I am truly grateful.

I appreciate the time and effort you put into [action taken]. Your [words/actions] have inspired me and encouraged me to [future plans/goals]. Your [advice/guidance] has been invaluable and I feel fortunate to have you as a [mentor/friend/colleague].

Once again, thank you for everything you have done for me. I look forward to [future plans] and hope to continue learning from you.

Best regards,

[Your Name]