When opening an overhead cleanout in the basement, tie a heavy-duty plastic trashbag around the cleanout, leaving room to get your hand in to remove the cleanout plug that you previously loosened. Cut a small corner of the trashbag bottom and put a 5-gal. bucket under the hole.
To reduce the worry of leaks in the ceiling from an upstairs water closet installation, I have found that if the closet ring is set too high, the space between the toilet and the wax ring is minimized, causing the wax to thin out.
When replacing the toilet handle on 90% of the toilets out in the field, it seems like all aftermarket handles and sometimes even OEM handles don’t fit in the square cutout of the porcelain all the time.