Pressing clay into mold.
If you are using a push mold, to avoid stains, it is best to mist a small amount of water into the section that you are going to press the clay in. This also means the the clay will be easier to take out.
If you have clay hanging from the top, you can use a kitchen knife to scrape of the extra clay on the top. But you must be careful not cut the mold or put scratches on the mold.
Cleaning the mold if needed to
You can use warm water to clean your mold if needed. You can use a sponge or a clean cloth to scrub gently at insides. This will help to remove left over clay sitting in the mold.