When I have tied on droppers. I use various types of fly patterns.
Have done well in the past with this type of pattern off of the SWE website called
Frosty Broadside (Tan)
That pattern with larger hooks.
-I use a Spro power swivel
-Tie on two lengths of 50lb mono/flourocarbon. Both off of the same eye on the swivel. With the opposite eye being the one I tie my main line onto.
-Depending on the set up it will typically be around 3-4 feet of mono leading to a snap so I can have the option of putting on different lures.
-Then the second length of line will be around half the length of the main leader. And I will tie on a fly direct.
this way you can fight a fish directly to your swivel. rather than going through a line to line connection leading to a swivel.