There have been several times when I've wanted to look back at something I've written in my journal, whether it be a favorite poem I've copied down, or the name of a book I was thinking about reading. I typically would have had to sift through my box of filled (or somewhat filled!) journals and flip through page after page, hoping to find what I was looking for. Inevitably I would get side-tracked, as my search would end up being a stroll down memory lane.
I have a couple of solutions to making your journals more searchable: create an Index or Table of Contents in your journals.
An index is a list of words, phrases, names or subjects that you perceive to be important. Examples could be the obvious occasions such as "prom" or "engagement" or your "son's birth." Less common examples might be "double rainbow" or "writing spider on front porch."
Table of Contents
A table of contents is just what you would find in a book or large document: a list of parts in the order in which they appear. You know... Chapter 1, Chapter 2, Chapter 3, etc., or Bill and Mary Met, Bill and Mary Fell In Love, Bill and Mary Got Married.
In my case, my journals are mostly about random nothings (though no less important!) and have the occasional nugget of wisdom or something of great importance that I don't want to forget. A table of contents probably wouldn't work well for me, because so much would be insignificant and that would make it hard to find the significant entries. So an index works best for me.
In a typical book, the table of contents goes at the beginning, and the index is at the end of the book. However I usually put my index at the beginning. When I begin writing in a new journal, I skip the first one or two pages, and label them as the index. Then, as I'm writing entries, if I think that a particular entry is something that I might want to come back to later, or is just something that I want to remember, I'll make a note of the subject matter and the page number on the index page.