In many cases, no needle is required when stringing with Stretch Magic, Elonga, Gossamer Floss or classic elastic cording. String beads directly onto the cord, or use an Igolochkoy needle/threader or Beadalon's Elastic Cord Needle.
Stretch Magic is super clear (or opaque black), and available in 0.5mm, 0.7mm, and 1mm diameters. It knots well, and easily stretches to twice its original length. Optional: Can be crimped instead of knotted!
Elonga and Gossamer Floss are SUPER STRETCHY shimmery multi-strand beading threads from 0.3mm to 1.0mm, and are easy to knot. All sizes are excellent for bracelets. Double the cord for extra strength, and add a drop of superglue for extra hold.
Classic elastic cord (not always available at Rings & Things) is popular for a wide variety of crafts and strung jewelry. It is strong and opaque.