Your purchase notes
Keep the details in one place.
Choose the intended use first. Throat sprays, fabric sprays and cosmetic mists share a bottle format, not a job.
Start with the purpose on the label, then note the ingredients, bottle volume and instructions. Keep products for different uses in separate shortlists.
Compare the cost per unit
Choose one consistent unit: pieces, kilograms, litres or prepared litres, as appropriate. Divide total cost by the quantity. Do not compare unlike product types on price alone.