1. Smallness: This is the most common and general noun form, referring to the state or quality of being small.
2. Small thing/item/object: This is a general way to refer to something that is small.
3. Miniature: This refers to something that is very small, often smaller than normal.
4. Petite: This specifically refers to a small size in a person, usually a woman, and implies elegance and delicacy.
5. Other specific nouns: Depending on the context, there may be more specific nouns to describe the small size, such as "crumb" for a small piece of bread, "speck" for a small particle, or "droplet" for a small drop of liquid.
The best noun form to use will depend on the specific context of your sentence.