one of my favorite journals is my cooking journal! I have one for each specific year and I write in it monthly, in real time. it consists of my grocery lists, farmers market lists, seasonal produce, meal plans for the week, recipe development (i also have a website i'm working on and a future goal is cookbooks so i'm always journaling this as I work on my recipes!!), meals I had out, dishes from cookbooks catching my eye, recipes i want to try... etc. really, everything food and cooking! it's more of a commonplace book of everything food related where I can develop and create recipes! it's fun to write the recipes out, and you have a place to make notes on what works, what didn't work, what to try, etc. Sometimes I even like to journal what playlists are going with the week - it's fun to see it along side all the cooking. it's always a fun look into the seasons too!
You can also use it to keep track on recipes / traditions you want to remember!