Bath Toys
After a while, bath toys can get all molded and gross. Whenever you buy a new bath toy, make sure to seal the hole before using it with some hot glue. This will stop water from going into the toy and getting molded.
Band-Aids
On a tight schedule, it can be difficult to find the time to run to the hardware store to find plug protectors. As a temporary replacement, use band-aids to seal the plugs when there are babies or toddlers around.