The answer may be a fun variation of fill-in-the-blank — crossword puzzles, known as crucigramas in Spanish. With software available for only the bother of a download, you can quickly create Spanish-language crossword puzzles with your own choice of words.
The free software, EclipseCrossword from Green Eclipse Software, lets you readily create your own word lists and definitions, so puzzles can be custom-designed for what you're trying to teach. One nice feature of EclipseCrossword that makes it particularly suitable for teaching Spanish and many other foreign languages is that it supports diacritical marks, so you can include words with the ñ as well as accent marks on the vowels.
The software, which uses Windows, is free, so you can't expect it to have the capability of professional software that will let you develop crosswords with the density and symmetry of the puzzles you'll find in top newspapers and magazines. But it is otherwise quite versatile, letting you specify the desired size (go too small, and the program will leave words out) and output format. You can print the puzzles directly, or you can save them to a Web page.
If you'd like to try some samples of crosswords made with EclipseCrossword, try these, in ascending order of difficulty: Numbers (Spanish crossword with English clues), Fun & Games (English crossword with Spanish clues), Fun & Games (same as the previous puzzle, but Spanish crossword with English clues) and Cuerpo y salud (in Spanish only). All are in a printer-friendly format. If you find them too tough, you'll find the answers listed on the following page.