It reminded me forcefully of a time when I had plenty of income, and my one splurge was expensive perfumes. I would buy them, but then I would "save" them for special occasions. It took watching my oldest daughter do the same sort of thing with a birthday gift of her favorite perfume and then our discussing it to help me realize how silly this was. I bought scents because I love them. They have a shelf life. I was wasting the perfume to NOT use it regularly. Since that time I regularly wear my perfumes and don't count the cost. They are an invaluable source of joy for me. The only way I can "waste" them is to let the scent sit in the bottle, to hoard them.
It surprised me to discover that although I had learned the lesson when it came to perfume, I had not learned it with other things in my life. Having fallen on lean times with the fears that come with not knowing where supply will come from in future, I have found myself living with a voice that says, "Use only what you have to; save what you can."
When we go through lean times it is very tempting to feel there is very little, not enough, and "waste not, want not" can become our constant mantra. Yet, in practical terms the attitude of not using what we have for the purpose intended, because we fear it will deplete us or our supply, puts us further into a poverty state of mind and instead of being blessed by what we do have, we hoard it and waste it.
If your motive is to help and bless others, to share joy or beauty, to enjoy what you have, I believe you can't waste what you use, any more than you waste an A note by using it to sing or waste the number 3 when using it to count.
I think the difference between intelligent use and truly "wasting it" is asking-- what is the purpose of the item? What is your motive in using it?
When you hoard what you have, fearful you won't have enough, that you are being depleted, you are wasting what you have.