The ends are sealed with a hot knife or a soldering iron. Then, a snap-swivel is clipped through one end. This can be tied between the main line and leader, or used as a sliding sinker ahead of a barrel-swivel separating the main line and the leader. Make up different lengths and weights to match varying currents and water depths. Use abrasion resistant monofilament when you're drifting.
Line takes a beating as it slides over rocks, twigs, and sand.
Check it regularly for wear and re-tie often. Line strength should be dictated by fishing conditions. Learning to recognize the take of a steelhead is one of the hardest parts of drift fishing. No two strikes feel the same. Some are soft and spongy, others sharp and aggressive.