開(kāi)頭：

It's good to hear from you.Knowing that you are going to ......,I'm writing these few lines to give you some advise about it.

主體主句：

I suggest you do sth,wich will help you do sth.

Doing sth will also help/is a good choice.

I think the best way of doing sth is to do sth,and you'll do sth/or you'll do sth.

I strongly suggest that you do sth,the purpose of wich is to do sth.

結(jié)尾：

I believe that you will take my suggestions into serious accout.Whatever you decide to do,good luck with you.