Coming back to Wikisource after a few months’ hiatus I have forgotten how to do common tasks like adding images to pages. Making notes here to refer back to:

• Open the purple links (problematic pages with the {{missing image}} template).
• Open that page on Commons and download the biggest available JPEG.
• Open the file in Photoshop.
• Command + Shift + U, to desaturate the image (if applicable).
• Command + L, to bring up Levels. Use the “Sample the image to set a white point” options to get the correct colors.
• Use the perspective crop tool if the image has a frame (lets you pick corners instead of a frame), normal crop if not.
• Save with a naming convention, usually – Title – Page Number – Book name.
• Use UploadWizard to upload images in bulk and copy over information like categories, date etc.
• Remove the {{missing image}} template in pages and use pre-established convention to add the images to the page.

Also see the help section on Wikisource, specifically about making some of these changes using a command line tool. I still need to understand what kind of templates to use when uploading the images to Commons.