Below are some more art ideas based around Van Gogh's style and famous pieces of work.
The fork painting idea carries on from using a knife to create texture in your painting. If your paint isn't thick enough you could mix in some flour (if you are able to get hold of any!) If you don't have the colours suggested you could use any you do have, it could be any type of flower - made up or real!
The portrait ideas could be a self portrait or you could paint someone else. See if you can use the swirls (perhaps for rosy cheeks) short lines (maybe eye lashes) and dabs (freckles or short hair)