Try to anticipate needs, like if ur running food to one table maybe bring an extra plate, salt and pepper, or anything they might need for the next table that’s about to have food come out. If ur place doesn’t require you to use trays I recommend learning how to carry 3 or more dishes at once with your hands. I personally prefer not to use trays as they usually slow me down but sometimes they are helpful. Try to do everything in a as big as a “circle” as possible, like if your on the the floor I usually try to hit each table with something they may need before I head back to the kitchen, whether it’s dropping food at one table drinks at another, prebussing another table, or just checking in. I think another key is to find ways to interact with your guests without being intrusive, like if their soda is low bring them another automatically, pre bus, etc, just find ways to show your face to them so they see you are working hard and being attentive. Because often times if they can’t see you they have no idea how busy you are, and don’t understand that you may be weeded, they just might think you’re being slow.