Kids can easily make colorful, textured window decorations by sticking tissue paper scraps onto contact paper. Ah, the simplicity of two ingredients (for the purposes of my revelry, scissors don't count as an ingredient).
If your kid is skilled with scissors, they can have at cutting up the tissue. I ended up jumping in too since my son was ready to move on after a few minutes. If you're willing to do all the cutting, this is a great craft for toddlers.
We cut up a few sheets of tissue paper in reds, pinks, and white. We kind of cut up more than what we actually needed. The large pile of paper scraps created a fun sensory play moment for my son, and he started throwing the pieces in the air like confetti, claiming we were having a Valentine party. Very cute, but to curb the mess, I quickly got a piece of contact paper in front him!
Last, we cut heart shapes and used a small piece of tape to attach them to the window (a tape circle pulls easily off the window). You could also call this a stained-glass heart.