You need this:
- white photocard
- Cutter with pad
- transparent double-sided adhesive tape (eg from Tesa)
- red felt-tip pen
- All-purpose glue (eg Pritt)
- Yarn in orange
- pencil
- scissors
It's that easy:
1. Prepare window ghost (template eg from the internet) in pencil on white cardboard.
2. Cut out ghosts and carefully cut the subtleties with the cutter.
3. Stick ghosts to the window with adhesive tape. Paint a small red heart on the little ghost and glue on the back of the thread. Attach to the window knob.