One thing I always followed in my relation with my son : Never enforce anything. Nothing. Let there be demonstration, slow and steady exposure to idea and concept. Give enough time and space for digestion.
He is 5+ now. More observations, varied questions. For last 5 years, he did not demand to establish Ganesa Vigrah at home. He enjoyed visiting different pandals and observe shapes and sizes.
This year too. Day 1 went into visiting relatives and friends sthapana. But in evening, there was question : Why not at our home?
Day2 : We started with our first attempt to give shape to our Ganesa. What did we use? We collected clay from the shore of Maa Narmada few months back.
What is planned for day 3 : Give appropriate colors so that a divide vigraha emerge from it. And yes, don’t fall in modern trap of calling it Idol or Statue! This is Vigraha(विग्रह). मूर्तिसे देवता स्थापन! तत्त्व स्थापन! जल स्थापन, पृथ्वी तत्त्वसे!
Day 4 to Day 10 : We will recite and memorize गणपति अथर्वशीर्ष. We will observe and note down different forms and their characteristics. And this will continue for next 5 years.
You may bring most beautiful vigrah at home but don’t miss to prepare one at home by self. Your involvement. Family’s involvement. Your vigrah is your prana representation. Reflection of your muladhar.
This (गणेश चतुर्थी to अनंत चतुर्दशी) is the open window of the year where mother nature naturally allow you get rid of excessive toxins built during varsha ritu due to मन्दाग्नि(low digestive fire with uncontrolled food habits).
1) Food during this time will help. Modak and Kheer, pomegranate
2) Devotion to Shri Ganesa will help. गणपति अथर्वशीर्ष
3) Spending time with clay will definitely help as it is पृथ्वी तत्त्व’s trait to absorb toxins from body. Plus, vigraha making yields concentration and attentive mind, result is observed in body cleansing. Stabilize Vata prakop.
Your imperfections in vigraha making will inspire you to correct the foundation. Foundation is in learning different art forms.
There is interesting conversation between King Vajra and Sage Markendya in Vishnudharmottara Purana about it.
King Vajra wants to learn art of Idol making.
He seeks guidance from Sage Markendya.
And Sage prescribes him to learn following art in sequence to become master of Idol creator.
Vocal music (Reciting Vedas) => Instrumental Music => Natya Shashtra => Chitra Kala (Painting in 2D) => Becoming sculptor
In short, it is important to realize cosmos, to express it so potently so that seekers can connect with God by concentrating on divine play captured in Idol.