I can only add to others points.
Those cheap nasty pre insulated things you get from Halfords etc and the super cheap and nasty crimpers for them are unbelievably horrid and should not be allowed near ANY motorcycle.
Proper crimps and a correct, proper ratcheting crimper are indeed game changers. As is having a selection of crimps so that you can actually choose the correct size for the wire.
Some shrink wrap to cover and provide some support finishes them off perfectly.
All only IMHO of course.