These are an inexpensive crimping tool which will save you a lot of time and effort if you have a large number of Molex C-Grid SL connectors to assemble, as used on our BMS modules and CAN connectors.
The tool has two sets of jaws, one for AWG24-28 and one for AWG20-24. Each set of jaws has a smaller side for crimping the pin to the wire, and a larger side for crimping pin wings to insulation.
With the right tool, crimping alone is generally reliable enough, though you may wish to add a touch of solder to pins after crimping for extra security.
Also available from Altronics (if that's easier for you), part number T1537.