Here is my favorite creative activity that we continue to go back to again and again at our house. Free painting. Free painting allows kids to get lost in the process of art making, it is the ultimate in process based art.
The beauty of painting with young children is that they don't need a prompt, they live and breath in the world of imagination. Give them paint and they will figure out what to do with it. Dip, brush, mix, splash, repeat. As they get older they will begin to show more restraint, eventually possibly even too much restraint.
Free painting is like free play. When they tell you that pink dot is an elephant, go with it, "Wow, what a beautiful shade of pink!" Free play is when children are at their most creative: making connections, processing emotions, replaying scenarios, and experimenting with new ideas. Kids were built to explore, discover and grow during free play, it only makes sense to carry this on through painting.
Free painting is a great activity that you can have ready for your kids when they get home from school. When kids come home from school they need time to transition into the world of home. Home is the place where they can be themselves, happy, sad, or scared, and still be loved and accepted. They've spent all day away from you, had a lot of fun, but also had to follow rules and stay on task while navigating stressful moments alone. They tried to be a "good student" all day. After free painting you may find that your kids are more willing to talk about their day and open up to you. Once they've had time to reconnect with their authentic selves, then they can reconnect with those around them.