Hi Sheila,
Are you using basic
silk bead cord? If not, what thickness of silk cord?
The normal method for finishing
silk bead cord, is with
bead tips. For these, you tie a knot inside the cup of the bead tip. With simple bead tips, the knot remains visible. Fold-over bead tips hide the knot inside what looks like a 3mm bead.
If you're using larger-diameter and/or flat cord, one of the styles of
end pieces or end caps on this page will work better. With a little more info about your cord (size/thickness, style), I can give you a good answer as to which findings and methods will work best.