Here are most of the tools I use for indexing:
Books! Big authoritative reference books. The black stand holding the book to be indexed would normally have page proofs on it. I always mark up a paper copy of the proofs when I index, though I use a PDF too. They’re both useful in different ways. In this case I just have my copy of A Writer’s Diary, and a pencil.
There are some useful online resources for geographical names and certain foreign language names, but mostly I use these, and the Library of Congress link to your left. Also the Index-L link which is the professional listserv, with archive. If they haven’t already discussed your problem, you can just ask them and get a free selection of opinions with arguments and modifications.
I started reading Henry B. Wheatley‘s How to Make an Index. It was published in 1903, in London, and I hope it will prove that there was no excuse for the the two-page horror I’m working to replace.
Mr. Wheatley was The Father of British Indexing, a prolific author and Pepys scholar, who could have written a good index for this book if he could have been bothered, and hadn’t died in 1917.
Below is a screenshot of my indexing software, which I love. It is to indexing what a word processor or a program like Scrivener is to writing: it can’t think or create for you, but it can speed and streamline and check your work in many wonderful ways.
There are three major indexing software brands, all good, all with devoted fans. I use Sky.
Here’s a screenshot of what my work looks like as I enter it. I type entries into the white fields, and they appear sorted on the left, in yellow. This is just me copying the existing index, which, to its shame, did not take long. Thank you 1980s high school typing classes. I am starting my index fresh on page one, however.
Everything else comes down to educated reading and thinking. Trying not to let your own subjective perspective have too much effect is a minor but important part of the work.
Anything you’re curious about? Let me know.