Japanese is difficult for me.

This week, I wrote my goal sheet for my task 1Q and 2Q. That sheet is used for my assessment at end of 2Q.

We have to write about what we must achieve, how we achieve them, when we complete their missions on the sheets two times a year 1Q and 3Q. Our boss assess our tasks result on the basis of them.

After we write it at beginning 1Q and 3Q, we interview with our boss. And they check these sheet.

Actually I am not good at writing documents.

There are many easy mistakes and strange expressions in my sheets.

This time,  I rewrote 4 times because of these.

Every time I interview with my boss, he point out errors like expressions and easy mistakes. 
I appreciate his indications, however I am frustrated with my writing skills

I have to improve my document writing skill. 
I try to search good way to improve it.