1. Paper Jack-O-Lanterns: Cut out orange construction paper into Jack-O-Lantern shapes and hang them around the classroom.

2. Spider Webs: Use white yarn or string to create spider webs in different corners of the classroom.

3. Ghost Garland: Cut out ghost shapes from white paper and attach them to a string to create a spooky garland.

4. Bat Cutouts: Use black construction paper to cut out bat shapes and stick them to windows or walls.

5. Cauldron Centerpiece: Place a black cauldron in the middle of a table and fill it with candy or fake spiders.

6. Haunted Classroom Door: Decorate the classroom door to look like a haunted house using paper bats, ghosts, and spiders.

7. Creepy Candles: Use LED or battery-operated candles and wrap them with white bandages to create a mummy-like effect.

8. Ghoulish School Supplies: Customize regular school supplies by adding spooky stickers or wrapping them with Halloween-themed paper.

9. Witches’ Potion Bottles: Fill empty glass bottles with colored water, add labels like “Bat Wings” or “Witch’s Brew,” and display them on shelves.

10. Spooky Silhouettes: Cut out silhouettes of witches, bats, or cats from black paper and hang them on walls or windows.

11. Doorway Spider Web: Use white yarn or string to create a spider web shape in the doorway, and stick plastic spiders onto it.

12. Graveyard Bulletin Board: Cover a bulletin board with black paper and create tombstone-shaped cutouts with student names on them.

13. Pumpkin Planters: Hollow out small pumpkins and use them as planters for spooky-looking plants or fake flowers.

14. Spooky Book Covers: Wrap textbooks or reading materials with Halloween-themed paper or black book covers.

15. Glow-in-the-Dark Eyes: Cut out eye shapes from glow-in-the-dark paper and stick them on walls or furniture for a spooky effect.

16. Monster Corner: Set up a designated “monster corner” with furry pillows, plush toys, and monster-themed decorations.

17. Skeleton Hands: Place plastic skeleton hands on desks or classroom surfaces to add a creepy touch.

18. Broomstick Pencil Holders: Attach wooden dowels to small buckets to create broomstick-inspired pencil holders.

19. Haunted Classroom Signs: Create signs with spooky messages like “Enter at Your Own Risk” or “Beware of Ghosts” to hang around the classroom.

20. Spooky Ceiling Decorations: Hang paper bats, spiders, or ghosts from the ceiling to create a spooky atmosphere.

21. DIY Halloween Window Clings: Make your own Halloween window clings using colorful adhesive vinyl or gel window clings.

I hope these ideas inspire you to create a delightfully spooky classroom atmosphere without breaking the bank!