Dear [Name],

I would like to express my sincere gratitude for your valuable advice that you provided to me [date]. I really appreciate your time and effort that you have spent to help me.

Thanks to your advice, I could solve [a description of what was solved]. It was really helpful and gave me confidence in my actions. I am glad that I could turn to you for help.

Thank you again for your support and valuable contribution to my life. If you have any questions or would like to discuss something else, please do not hesitate to contact me.

With respect,

[your name]