eTapestry already has a standard query that does this for you. It is called LYBUNT. LYBUNT stands for Last Year But Unfortunately Not This. So in other words, donors that gave last year, but didn't give this year. There is also a Last Fiscal Year But Unfortunately Not This (LFYBUNT) query if your organization runs on a Fiscal Year.
  1. Click Queries on the menu bar
  2. Click the LYBUNT & SYBUNT category
  3. Click Preview under the LYBUNT query
You don't want to click the word LYBUNT to open the query itself. It is a standard query so you can't make any edits.

You may also be interested in building some of your own LYBUNT queries to have more control on the results being returned:
For additional information on LYBUNT and SYBUNT, please refer to What is a LYBUNT and a SYBUNT?