so i never really understood how multishipping worked because i just made people poly if i thought there could be another person

here's a few questions for scientific purposes:

1. what r a few characters you guys just shove a whole bunch of ships on?

2. when ur writing/drawing/whatever, do you usually stick with one main ship or do you just put it on shuffle???

3. do you defend most of this with headcanons, or is a good amount canon?