Here is a by-no-means-comprehensive list of what I keep in my bathroom (also under my kitchen sink, depending on the item). It is a general list of things that I like to keep on hand. Keeping some things on hand at all times makes creating your own cleaners, beauty products, and first aid materials easier. Obviously, I'm not telling you that you should keep all of these things and these things only on hand, this is just meant to be a guide if you are just starting out, or if you like how I do things and want to set up your own bathroom or kitchen in a similar way. Use this as a reference, but be sure to throw in your own flair to suit your family's specific needs!
-I'm a sucker for a good first aid kit. That must be why I have slowly taken small kits from here and there or this and that and created my own master kit. Seriously, I had to buy a tackle box...but it's all in one place and I haven't bought bandaids in years. In my monster of a kit, I keep instant ice packs, triple anti-biotic ointments, hand-warmers, gauzes, and wraps, and slings, and bandages...oh my! I have a ton of alcohol prep pads and the like. I even have chapstick, hair ties, and motion-sickness preventing wristbands.
-I keep a hefty supply of non-prescription painkillers (aspirin, acetaminophen, and ibuprofen) as well as meds for colds, and meds for stomach issues.
-I keep vitamin E capsules handy and as well as multivitamins and silver hydrosol (for sore throats).
-I also keep a big bottle of isopropyl alcohol and hydrogen peroxide.
Keeping It Clean:
-I have been slowly moving away from buying commercial cleaners in lieu of making my own, but I still keep some of the essentials: glass/mirror cleaner, general all-purpose cleaner, and Comet for the tub and toilet. I want to invest in some ammonia at some point, but have yet to do so.
-I keep a hefty supply of white vinegar and baking soda for cleaning purposes.
Bath and Beauty Products (and the stuff to make them!):
-Like anyone, I have shampoo, conditioner, and bodywash in my bathroom, along with shaving cream, deodorant, mouthwash, detangling spray, body spray, handsoap, facewash, toothpaste, ect.
-I've started keeping witch hazel to make my own facial toners and I'm starting to play with the idea of making my own facial cleanser as well.
-For now, I am using up what I have in the way of body and face lotions, but I plan to soon be making better, cheaper versions of that myself as well.
-I wear contacts, but I buy them online in order to get them cheaper. I have recently begun to save my leftover contact cases to hold homemade lip glosses.
Odds and Ends:
-Leftover contact cases and other containers for homemade products.
-Towels, washrags, bathrobes, and my husbands unwanted old socks (used as cleaning rags)
-A gallon-sized back of samples from hotels, meetings, etc. to use when traveling or just so I can put of buying product X a little longer.
-Hair stuff like combs, brushes, hair ties, bobby pins, etc.
-Makeup of various types in various colors...some for looking pretty, some for looking scary (I love Halloween!) [Also various other womanly products.]
-Vegetable produce plastic bags that I recycle as bathroom trash bags because they are the right size for my bathroom waste basket and don't cost me a dime.