I always start by adding a bunch of vegetables first because veggies will help flavour the broth, and they also tend to take longer to cook. This is the "communal veg" which means anyone can take from this pile. Keep adding communal veg as people take them.
Things that can live in the hot pot for a while such as tofu and fish balls/fish cakes, you can just add a bunch in for communal use. Although this depends on the group of people you're with, some people may prefer cooking their own proteins and not be happy if you've taken something they put in.
Glass noodles take about 2 minutes, but can be in there a little longer without overcooking. I just put a bunch in my " sieve ladle" and let it hang out for a couple of minutes. When you take it out, some will probably have fallen out of the ladle so it's good to fish around a bit with your chopsticks.
Thinly sliced meats, cook in your sieve or dip with your chopsticks for literally 10 seconds just until it's cooked through. Don't let thin slices of meats linger in the pot!
Speaking of chopsticks: the hot pot etiquette is that there are personal and communal chopsticks. Personal chopsticks are for eating. Communal ones are for putting things into the hot pot and taking them out. I can never keep them straight and always end up eating with the communal chopsticks lol! But honestly, when I eat with immediate family we don't care who's using what chopsticks, especially since they will be "sanitized" in the boiling broth anyway!
Do not let it boil away! Keep your eyes on the heat. You want to start out on a full boil but once food goes in, a simmer is a good place to be so you don't overcook everything so quickly and you also won't lose so much liquid so fast and run out of stock.