To make a simple, versatile veil you will need a rectangle of linen. The short side needs to be long enough to tie around your forehead and behind your neck. About 60-70cm should be fine. The long side should be about double the short side.
Cut the linen and hem down non-selvage edges with a hem stitch or for fine fabric, a tiny rolled whipped hem.
To wear, put the centre of the short side of the veil on your forehead, bring the corners behind your neck and tie. The rest of the veil can hang from your head, be brought across the throat and tucked into your dress neckline or twisted up, wrapped around your forehead and tucked in.