An art inventory spreadsheet. Make notes about the work itself, if it’s out on consignment or in your possession, if sold and to whom. If it’s out on submission, record the name of the exhibit along with the dates the exhibit begins and ends. Modify it to suit your needs. This is just a handy starting point, or you can use it as it is. Mostly, I use it to help me remember which works are submitted to what exhibits, and I keep the addresses and contact info for those exhibits/submissions.