You may be tempted when drawing ceilings, particularly when defining the edges manually, to do more than one room or ceiling at a time. (see images below) If you notice when using the 'auto' tool, that it only does one room at a time. If you select more than one room at a time, or draw the boundary for more than one room at a time, you are probably doing it out of a mere desire to save time, but in reality you are causing yourself more headaches and time down the road.
When placing ceiling tags to tell the type of ceiling as well as it's height, it will automatically snap (if using no-leader) to the center of the ceiling. If you have drawn more than one space's worth of ceiling, then when trying to place the tag, you will need to exit and re-enter the annotation command, and when you click it will place the tag in the exact same spot as the first. Unless you know it is doing this, you will have no idea where your tag is and probably try to click multiple times. If you do several ceilings, or soffits in a line down a long building, this can make the annotation process very tedious and time consuming, because instead of showing up at the center of that particular object, you are instead showing up at the center of the entire assembly and you will be required to move each tag to its appropriate place.
If you do each space separately, tagging becomes much easier as you can keep the command active and simply click on each ceiling. If you want to adjust one ceiling, you are able to without affecting a bunch of other ceilings. In the world of integrated construction, quantity take off's (QTO's) the sharing of the model and LOD modeling each ceiling separately allows all the relevant parties and trades to do what they need to with the model, perform take offs and find out the true properties of the object, and is almost a requirement for the production of a Level 400 or Level 500 model.
Sure, it may take a little more time initially, but it is a 'best practice' and will save you time down the road.
