The last thing you should do when editing is sharpen. Using Unsharp Mask can cause oversharpening and make the image appear unnatural. Here are some USM settings to use with great results to make the digital images look more like those using film.
 
Tips for enhancing digital photos by using PS Unsharp Mask settings designed to remove haze and make them more clear while retaining a natural look and making them appear more three dimensional and like those taken with film. These can be used together, and after any particular area is selected and sharpened. You should use them both in the following order.
 
1. Open the file. Choose File --> Open --> Enter the image name to be fixed.
 
Use Either The Light or Stronger Setting:
2. Choose Filter ---> Sharpen ---> Unsharpen Mask to display the Unsharp Mask settings. Start with (For Light) Amount: 20% - Radius: 30 pixel - Threshold: 4 levels. Click OK.
Or
2. Choose Filter ---> Sharpen ---> Unsharpen Mask to display the Unsharp Mask settings. Start with (For Stronger) Amount: 20% - Radius: 60 pixel - Threshold: 4 levels. Click OK.
 
Then repeat with the following settings:
3. Choose Filter ---> Sharpen ---> Unsharpen Mask to display the Unsharp Mask settings. Start with: Amount: 500% - Radius: .2 pixel - Threshold: 0 levels. Click OK.
 
4.  Reapply Step 3 as needed, changing only the amount setting from between amounts of 100-500. Careful not to over do it.
 
5. Choose Save As to save the file with a new name.