Two bottles can both say conditioner and still belong at different points in your routine. Before adding one to your basket, look for the words rinse out or leave in and read the directions for that exact formula.
Rinse-out conditioner belongs in the washing step
Use a rinse-out conditioner as directed after shampooing, then rinse it away. Follow the label for the amount and time rather than treating every conditioner like a mask.
Do not turn a rinse-out product into a leave-in by leaving it on longer or diluting it in a spray bottle. The American Academy of Dermatology explains that the two types are formulated for different uses.
A leave-in stays on the hair as directed
A leave-in can help with detangling and manageability between washing and styling. Check whether your chosen product is meant for damp hair, dry hair or both; a spray and a cream need not have the same instructions.
Start with the amount on the label and distribute it where directed. More product is not automatically better. Do not assume a leave-in provides heat protection unless its label specifically says so.
Compare the exact bottle, not only the brand
Write down the range, product name and size of a conditioner you already like. A brand can sell a rinse-out conditioner, a mask and several leave-ins in similar-looking packaging.
Compare the cost per 100 ml or 100 g using equivalent units. A larger pack may cost less per use, but only if it is a formula you want and will use. Check the full delivered basket price before deciding.