I purchased some fabric at a garage sale and it has that "other person" smell. I know I need to wash and iron it before I put it in my stash. I usually don't wash new material that I by from LQS. What will happen if I don't use this for a while and when I decide to use it I forget that it has been washed and I use it with non-washed fabric? Will I have a problem? Now that I have talked this out, I know, put a note with the fabric that it has been washed so that I will know to wash the fabric that I use it with. Well that problem solved. Thanks anyway.

You said it before I could type it

yes, pin a piece of paper to it, so you know it has been washed or cut a corner, some way you will know that it has been washed
or pinking shears along the edge

on a shelf of your fabric just have a shelf for washed fabrics

You said it.

I have lots of pieces of fabric from my mom's stash with little notes pinned on them stating the exact measurment and if it had been laundered.

Isn't it funny how we can reason things out just by typing it

It is possible to remove smells by putting them in a dryer with a WET towel and some fabric softener sheets. The damp from the wet towel transfers the fabric softener. If you use liquid softener just pour some on a wet washrag and put in the dryer. This is what we used to do before fabric sheets. Maybe that is where the companies got the idea.

I prewash all of my fabric. I clip the corners first. Then if it gets mixed up with a new purchase in my sewing room I can tell which fabric still needs washing.

I pre-wash all my fabrics before cutting for a quilt, but I don't always do it right when I buy it, so I have a mix of washed and unwashed fabrics. It usually is pretty obvious when a fabric has been washed, even when pressed, they don't ever look as smooth as when unwashed,also the cut ends usually will ravel a certain amount when washed.