I make small little sachets from muslin 'tea bags' I used to buy at Whole Foods. They only hold about 2 tablespoons of very fragrant dried lavender and cedar shavings which I bought online.
I put one of these on every shelf of my fabric, in each container of strips/squares/triangles, and in each large container where my quilts are stored. Never had a bug problem, the fabric always stays fresh and a bit sweet. Some of these sachets I've had for years; to freshen them I only have to roll them a bit between my fingers and the scent is as noticeable as ever.
Jan in VA.