[Tristan Lall]

• Use good quality finely stranded wire. (I like welding cable. Car stereo cable is fine if insulation durability isn't a huge concern.)
• Use the right terminals for the wire. (I like to use the solid copper, tin-plated crimp sleeve terminals designed specifically for the wire gauge, with a #10 screw hole.¹)
• Use a a high-quality crimping tool. (Last time I bought one of those, it was less than $40 CAD. $65 is the best price I could find today; they're often well over $200 now. Consider the style Home Depot currently sells, but be aware the results may not be satisfactory due to the differently-sized crimping dies.)
• The barrel of the terminal can usually accommodate two crimps with the tool. The whole process is completed within about two minutes (once you get used to stripping fine-stranded wire with a utility knife, without nicking the conductors too badly), and I've never had one fail.
• The same procedure applies to Anderson SB50 and SB120 terminals; use the sleeve-type (not stamped) ones, and crimp once.

¹ FIRST has often supplied ones with a Ø0.25 in screw hole. These don't fit the provided battery screws nicely.