Crimping connectors may be fine for wire-to-wire connections - and handy if you wanted a re-configurable harness. But sometimes, soldering is your only reliable method for connecting metallic elements together.
For example, wires or capacitors or resistors to pots (potentiometers): they just have to be soldered.
You can learn how to do this; it just takes practice. The most common mistake I see is cold connections or flux insulation and both happen when the connection is not heated properly. This can be due to one or more of these causes:
- too cool soldering tip
- too quick/short heating of connection
- improperly tinned wire
- poor physical connection before soldering
All of these are easily remedied with a little patience. There are dozens of YouTube videos that show how to make good soldering connections. With minor variations, most recommend making a good, steady connection, heat the connection (not the solder) and allow the solder to flow over the connection.