It is a good gesture to thank people who have shared some useful advice or thought with you which has helped you take an important decision. Such people are rare and you must not leave a chance to thank them for their help.
If someone has helped you with his advice then you must thank him by writing a formal thank you letter expressing your gratitude for his useful suggestion. Here is a format sample of thank you letter for advice which has been given below for your reference. Use it for creating your customized letter.
Sample of Thanks For The Advice Letter
11, Park Avenue,
Date: 6th November, 2015
42 Richmond Street,
I would like to thank you for helping me with selecting the best college for my graduation. I must tell you that I was in deep confusion as I had no clue which university to apply for but then you really guided me short listing the best universities for the course I want to pursue. Your advice has really helped me as now I have been selected in the New York University which would have otherwise been impossible. You have been a great friend to me and you have always extended your help as and when I have needed it.
Once again I would like to thank you for your valuable suggestions which have helped me made the right selection.