I'm sure you'll succeed with/through your hard work．One possible version
Dear Linda，
I'm very glad that you are learning Chinese．I know it isn't easy to learn a foreign language，but I have some ideas that may help．
Firstly，it's very important to listen to the teacher carefully in class and make some notes so that you can go over your lessons later．【高分句型一】Secondly，try to catch every chance/take every opportunity to practise speaking Chinese，both in and out of class．Don't be afraid of making mistakes．Then try to listen and read more in Chinese．What's more，you'd better plan your time well and study it regularly everyday．【高分句型二】
Above all，I think you should be confident in yourself and don't give up whenever you meet with difficulty．【如何学好英语的几点建议】
I'm sure you'11 succeed with/through your hard work．【总结全文】
Best wishes!
Yours，
Li Hua I'm sure you'll succeed with/through your hard work．One possible version
Dear Linda，
I'm very glad that you are learning Chinese．I know it isn't easy to learn a foreign language，but I have some ideas that may help．
Firstly，it's very important to listen to the teacher carefully in class and make some notes so that you can go over your lessons later．【高分句型一】Secondly，try to catch every chance/take every opportunity to practise speaking Chinese，both in and out of class．Don't be afraid of making mistakes．Then try to listen and read more in Chinese．What's more，you'd better plan your time well and study it regularly everyday．【高分句型二】
Above all，I think you should be confident in yourself and don't give up whenever you meet with difficulty．【如何学好英语的几点建议】
I'm sure you'11 succeed with/through your hard work．【总结全文】
Best wishes!
Yours，
Li Hua