New plaster must be fully dry and cured before painting. The drying time for plaster ranges from 1 to 4 hours, but the curing process can take more than five days, depending on various factors, including humidity levels, temperature, the amount of plaster used, and airflow in the area. You should always apply primer before painting plaster.

A common cause of separation between a wall and the ceiling is truss lift—this can happen to the ceiling of rooms directly under the attic when the seasons change and wood building materials dry out, shrink, and shift. Roof trusses often dry out at different speeds, and if the bottom pieces dry out faster than the top pieces, they can shrink and pull the attached drywall away from ceilings and walls, causing cracks. Fortunately, truss lift is only a cosmetic problem, not a structural problem, and you can fix it by separating the ceiling drywall from the roof trusses, and patching the cracks.

You should always hang drywall from the top down. Starting at the top makes it easier to create a straight, tight line between the ceiling and the wall. Any gaps that occur will be at the bottom, where they are easier to manage. You can either cut the bottom piece of drywall to fit the remaining space or cover the gap with baseboard trim. Additionally, starting at the top is physically easier, as you won't have to fit the top sheet into a tight space between the lower sheet and the ceiling, or try to balance the upper sheets on the lower ones while securing them.

Whether you can reuse a drywall anchor depends on its type, material, and how it is removed. Plastic anchors, such as expansion or self-drilling types, are generally considered single-use because they are designed to expand and are likely to break or become deformed upon removal. Metal anchors, like toggle bolts, are more durable and can often be reused if they are not damaged during extraction. However, with toggle bolts, the toggle mechanism can fall inside the wall when the bolt is removed, making it difficult to retrieve. If an anchor is damaged or must be cut for removal, it cannot be reused regardless of its material.