Depending on which motif you have chosen, start by priming the terracotta-pots in white. Always do this where you want the motif to be later. But make sure you cover a larger area.
If you are using straw silk paper for banderoles, for example, go around the terracotta-pot once with the paint. Then roughly mark the area that needs to remain free or white for the motif. You can also apply the stickers or the straw silk paper beforehand.
Then cut a paint sponge into four pieces and dab the structure paste onto the pot. But leave the motif area free.