If you rewire your motorcycle, it doesn't take long before you come to the part of the connectors, and the connectors is also a part that needs to be done properly. Solder or crimp? Soldering is a bit of a magic art that needs learning and practicing. You also need a bit more time of course, electricity! Heat damage to the wire is also to be avoided.
Crimping is easier and quicker to do and learn, but can still be done incorrectly. Reliability is about the same, either process done incorrectly will fail, and even though crimps will eventually corrode, the wiring and the connector will corrode just as quickly.
Decent correct tools are also a good starting point. Would you use the cheapest spanner? So why use the cheapest crimp tool? Some advocate crimping the connectors and then to run a little solder into the joint. Personally, I don't think much is gained in most cases, though occasionally there are some connectors for which a little solder in the joint will be useful. So what connector system do I recommend? There is a system called the F-crimp that has a separate, clear plastic cover and F-crimp is a type of solderless electrical crimp connection. F-crimp is a more mechanically robust crimp connection compared to the common barrel-crimp type readily available at retail locations. The DIY tool for these cost about 500 THB and does a decent job. An easier job can be done with a bit more costly version of the tool.
When fitting a connector think what can happen if it falls apart in use? Can the live part touch earth? Can a cover avoid this? Will the sleeved item be live instead of the bullet? Remember to push the bullet up into the snap connector, there is a Ripaults 'closing' tool, which looks like a cheap pair of pliers but usually costs over 500 THB. Use a small instrument screwdriver behind the bullet.
Now let us consider why we have a loom? It is to connect all the electrical bits together. Yes, but the manufacturing consideration is to prevent several lengths of separate wiring, thus all the wires are tied together as one piece 'a loom' if and where possible. Some motorcycles have a headlight sub loom, merely for ease of construction. If for any reason you find you want some wires run in a separate sub loom then no problem, do it.
Now, why do we actually have a connector? Simple. To be able to change a part quickly and easily, such as a rear light. So if it looks like you'll have connectors in odd or inaccessible places, ask yourself 'why is that connector there?' - perhaps you don't need it.