I have my tools and spare tube in a seat bag. One of my panniers (Koki Bagatelle) is my 'main' one. Rain jacket is in a ziplock bag to compress as much as possible, and goes in the large internal zip pocket. My clothes get rolled up into a compression bag, with shoes on top. Anything small and losable (pens, etc) goes in the small internal pocket, and wallet goes in external zip pocket. So basically, that pannier is for my daily essentials. The other pannier (homemade from a shopper-style purse) is normally empty, but attached to the rack and rolled up. It gets used for random large things that have to go back and forth to work, groceries, etc.