Before you take on an editor you should always get a sample of their work.
This is not just to make sure that they can do what they say they can, but so they can offer you an accurate estimate of how long the work will take, how much it will cost and what level of editing is required. It also tells you if that editor’s style is compatible with your own. It could be said that a sample is a precursor to a successful business relationship between author and editor.
Samples look at:
- Language and flow.
- Grammar and punctuation.
- Dialogue (where applicable).
- Character and plot (where applicable).
- The style of the writing and whether it is audience appropriate.