Use old furniture. Cut it down to size as needed. Walk through your house with your child to find that special study corner. It need not be big, but it needs to be personal. Paint cardboard boxes or orange crates for bookcases.
Latex paint is easy to clean.
Save children's artwork from school for the extra touch. A study place can be a desk, or it can be a modest lapboard for a child to use atop a bed. What is basic to both is their message that studying is valued in this house. There is a better way than nagging children every day about homework. You need paper and a marker.