Step 7: Finishing the ends
Take your spades and solder them to the ends of the cable. I used a bench clamp to help me do it easily.
Now, take your smaller heat-shrink tube and slide them over your spades. A red one should be used on the positive side and a black one on the negative side. Make sure the heat-shrink overlaps onto the spade. This will give some strain relief and it makes it look better. Apply heat.
Notice that I didn't slide the heat-shrink on before I soldered on the spades. I did it this way because heating the spades with your soldering iron takes a long time and causes the copper in the wire to heat up. This can cause the tubing to shrink on you before you're ready for it. So, get some spades that are small enough to slide your tubing over.
Next, take a piece of the larger black tubing (about 4 inches) and shrink it around where the tails come out of the corrugated/braided tubing. Apply some heat to it, but be careful because if it gets too hot, the nylon braid will burn.
Repeat this process on both sides of the cable.