They will be full of ideas for design as well as content. Start a clipping file from newspapers and magazines. If the clippings don't lead to a story, at least they may produce a filler to replace a last-minute deletion. Don't forget to tell your readers about your need for news in every newsletter issue. For many, writing is the hardest part of newsletter work.
Writing is work.
Editors often think good writing comes naturally - on the contrary, writing is a learned skill and requires constant practice. Good writers write, rewrite and rewrite again. Good writing reflects a personal style. It must be as simple and direct as speaking. Read aloud some of your own writing.