Use dishwashing soap bottles, liquid laundry soap bottles, and liquid soap bottles too. After you use it all up, don’t rinse it out. Fill with water and label bottle “soapy water”. That way you will have it to use for sanitation and not have to use precious drinking water for washing dishes, cleaning, personal hygiene, etc.
You can improve the taste of stored water by pouring it back and forth between two containers. This will add oxygen to the water and improve its taste.