As a handmade business, once you accumulate a certain amount of inventory it starts to become a priority to ensure that you have it organised in some sort of fashion that allows you to access it quickly and efficiently. Otherwise, time you could be using to produce your products and grow your business is rapidly used up by rummaging through mislabeled boxes, scratching your head and mumbling "I'm sure I put it here somewhere..."
The best first step to a well organised inventory is to develop a location naming system for all stock: this includes both your materials and finished products. While this sounds complicated, it's really just a case of deciding on a way to group together and label your inventory using a consistent naming system of your choosing.
For small craft operations, you will most likely not be dealing with multiple warehouse situations that require Ikea-esque aisle descriptors, so you can be much more creative with your naming.
Above all else, each Location name should be unique - you need to be able to clearly picture the exact place in your mind when you think of the name. You'll also need to be consistent with applying locations to all of your inventory for this to work well - it's no use having a great location name system for your flour if you can still never find your baking powder.
The naming itself doesn't need to be too complex or cryptic: a good way to start is by thinking of the terms that you currently refer to the places you store your inventory. Maybe you have an area for fabric in your storeroom that you refer to as your "Fabric Stash" - this would be an ideal starting point for naming your inventory location (FABRIC-STASH). If you have a blue box that contains your buttons and clasps, then this would again be a good candidate for a location name (BLUE-BOX).
Don't name it based on something that can move around - for the example of using the Blue Box above, you'll want to ensure that this box doesn't leave a certain area. If so, it may be better to call your location where the box actually lives as this is going to be where you will most likely find it (i.e. BOOKSHELF).
Depending on the types of materials in your inventory, creating zones around your rooms rather than specific storage containers may work better. If you know that "STUDIO-BLUE-ZONE" is in a specific corner of your workspace, this instantly narrows down your stock search significantly already.
You'll want to try and label each of your locations - if they are boxes, a prominent sticker with the location written clearly at the front is a great idea. Zoned areas of rooms may work best with signage added to each wall - an A4 printed sheet is all that is needed. For zones, colors can work particularily well: it can be much easier to visualise colors in spaces than if you named each zone after something clever like gods from Greek Mythology (although if you want to go with the Zeus approach, that's totally fine too!).
If you have more than one room, you might like to create a naming system incorporating both room and zone. WORKSHOP-BLUE, for example, would indicate that your material is located in the workshop, in the blue zone corner.