How do I know when a product has actually gone off?
Trust your nose first — if an oil or a cream smells sharp, waxy or like old crayons, that is oxidation and it is time to stop. Separation that won't mix back in, a change in colour, grittiness in something that was smooth, or any stinging on application are all reasons to let it go. Be strictest with anything that goes near your eyes or on broken skin, particularly mascara and liquid liner, which are worth replacing on schedule rather than on sentiment, and ask a pharmacist or your GP if a product causes a reaction you can't explain.
Does using things up actually save money if I still buy new ones?
Only if finishing changes what you buy next, which is really the point of the exercise. By the time you empty a tray of stalled products you will know exactly which textures, scents and finishes you reach for without thinking — and that knowledge is the thing that stops you spending on another hopeful bottle that ends up at the back of the cupboard. The saving comes less from the empties than from the sharper shopping list afterwards.
Nobody needs to turn their bathroom shelf into a moral statement. But there is a quiet satisfaction in scraping out the last of a jar you genuinely liked, and in knowing precisely what you want to replace it with. That is not deprivation. It is just paying attention.
