The hardest part about making sense of an under-sink cabinet is how to use the vertical space with all the plumbing that gets in the way. This type of organizer is perfect. They are narrow and the bins slide out so you can easily access what you need. These are great under the kitchen sink for cleaning products and tools or under the bathroom sink for toiletries. There are a few different types out there, some you can screw the base into your cabinet for stability. They are usually an open mesh, wire or plastic to allow drainage so make sure to get one that will support your needs (don’t want large holes if you’re putting small hair clips or nail files in the bin). Where can you go vertical and corral like items so you are more organized? Bathroom, kitchen, laundry room, first aid supplies, bath toys and bubbles or the garage sink? Measure your available height and width and think about what you will store in each bin, making sure your items can fit with the given clearance (small jars on the bottom, tall bottles on top for example). This one is from The Container Store.