I have recently auctioned some work for charity & people have donated money on top of that. What is the best way to catalogue that in my accounts?

I can help in adding these transactions to your account, @userwgmartin-silver.

We are following HMRC's SA103F categories for self-employed individuals. To select the best category that suits this transaction, I suggest consulting an accountant for guidance with the best category to use.

Here's how to add a transaction and add a category:

1. Go to the Transactions menu and click on the Add transaction button.
2. Provide all the necessary information like the date, transaction description, amount, type, category, notes, and receipt.
3. Click on Save.

Check this manually add transactions in QuickBooks Self-Employed article for detailed guidance. Here are the SA103F deduction categories we have in QBSE: About SA103F Categories. 

Let me know if you need further help in managing your transactions. I'm always glad to help in any way I can. Have a great rest of the day!