I have included some examples of things commonly used in Biology labs. Mixing either of these with Strong acids will produce heat and may result in a fire or explosion. Isolate in a cabinet away from Strong acids. Store separate from Strong Acids and Oxidizers. Acetic acid and formic acids are combustible and might be stored in the Flammable storage cabinet if you do not have location reserved for Weak Acids.
Oxidizers can cause spontaneous ignition if mixed with a combustible material.
Oxidizers must be separated from other chemicals and stored in a separate cabinet. Make sure everyone in the lab understands why these separations are made. Provide clear lables on the cabinets. The Office of Environmental Health and Safety at the University of Alberta usually recommends that people not store chemicals below sinks or in other cabinets with utilities that may need repair. However, most labs do not have the luxury of not using spaces like this and I think it is acceptable to use them as long as you understand you will be responsible for clearing it out should workers need to make repairs in that area.