I use leader links. They are quick & painless, especially in you are using tapered leaders.
Eagle Claw Leader Link - 5 Pk. Kittery Trading Post
They don't force a hinge at the end of the fly line either.
Only knot required is a simple over hand knot.
To instal a new leader: force the butt of the leader out of the link, clip the overhand or double over hand knot off and slide the old leader out. Then feed the tippet back threw the link and pull it threw. Tie an overhand or double over hand knot and pull snug. Clip tag and tie on what ever you want for tippet.
I have never be able to figure out why more people don't use this.