I encourage teachers to order at least 1 day in advance (at least not “I need it now” or “I need it this period”.) so I have time to prepare and assist better. For example, some chemicals don’t dissolve fast. Limewater needs to be shaken every few hours for a period of 24 hours to ensure that as much calcium hydroxide as possible dissolves. I encourage teachers to keep basic equipment like glass rods and test tubes in their classrooms and to take care of them. It’s better if students can wash them and put them back in the cabinets since we don’t have a laboratory glassware washer. If there is one or two difficult items to wash, no problem, the teacher can give them to me, I can soak them and find a solution.