If you’re a mystery writer, chances are you’ve read a lot of mysteries. If you’re a romance novelist, you’ve probably read a lot of romance.
Everyone knows that reading a lot in your genre helps you write better. The same is true of queries. Reading queries will help you write queries.
That’s part of the reason I wanted to do query critiques on the site. Not just to benefit the people receiving the critiques, but the ones reading the query letters as well. When you read other people’s query letter’s you notice things. You can see how your own letter stacks up.
Read as many as you can. It will help you when you go to write.