I am writing to express my views concerning...
我写此信来表达我关于……的观点。
You have asked me for my advice about...,and I will try to make some conducive suggestions.
对于你来信问我关于……的事,现提供几条有益的建议。
It's important to.../It helps to...It should be a good idea to... ...
很重要/有帮助/是个好主意。
I am writing to put up some suggestions concerning...
我提出几条有关于……的建议。
Please take good consideration of my advice.Thanks.
请仔细考虑我的建议,谢谢。
I hope you will find these proposals/suggestions/recommendations helpful/useful.
希望这些建议对你有帮助。