Been thinking about it this morning. I'd be hesitant about tinning the clip before inserting the wire, as the Cardas clips I ordered look like barrel construction.
Thinking I'm going to tin the wire. Then get the wire into the barrel using a "third hand" to hold wire and clip in a vertical position. Barrel end that connects to the cartridge being up. Then solder using a long pointed SMD tip. Gravity will help keep the solder where I want it if I don't overfill it.
Of course this may change once I receive the clips and really see what they look like. Gotta be careful soldering anything with real gold plating, solder really wets and flows fast.