For almost every fabric you got a special needle, like for stretch or leather.
In the past I had the problem that I got a lot of used / blunt needles in there packing. Sometimes it was so bad I noticed I had no more good needles for the fabric I wanted to sew.
So I came up with a simple method to remind me which needle I used before, this way I only had one used needle in every packing and I know for sure I had sharp spare ones as well.
When you used a needle and wand to store them back in there packing, Put the needle upside down (the flat side on top) this way you know its used and might be more blunt than the others.