the bare wire. That makes the wire less likely to unwrap a bit and short this wire to that
wire (when you are digging around under it trying to find a problem?) and makes the
connection quite a bit stronger.
For the soldered ends, I first tin the pin with a dab of solder.
Then make a tiny hook in the end of the wire, slip it over the pin and hold it steady while
you solder it together. Usually that means just touching the tip of the iron to the connection
for a second or two.
Those connections tend to be more fragile as the wire is connected solidly and wiggling
it can cause it to fracture at the solder joint.