I've just finished the 44th volume of the personal journal I've kept for over ten years. In that time I estimate I've written (by hand, with a pen) 650,000 words, which is about the same as four to five average length thrillers. In that time I've learned a thing or two about keeping a personal journal. You can read about some of them in my Kindle book on Journalling. (You don't need a Kindle to read it; any tablet, smart phone or PC/Mac will do, using the free Kindle app.) It costs less than a pound (or your local currency equivalent.)
View on your local Amazon site
Journalling School: A Short Course in Personal Journalling provides a straightforward and insightful guide to those wishing to start a journal or those who wish to return to or reinvigorate their journalling. Covering a wide range of aspects and including exercises and questions to ponder, this will inspire any journal keeper or would-be journal keeper.