This decoration idea is demonstrated through steps in the images below. I have chosen arugampul and sampangi. Both are tied on one side only to get a semi circular shape. The ends can be tied to get a circular shape garland that can be placed at the feet of Lord Ganesha. If it is left in the semi circular shape it can be used to decorate the image of Lord Ganpathi.
These rangoli and other puja rangoli are in Rangoli for Puja
Puja mandir decoration with rangoli
Then a banana leaf (nuni ilai in Tamil ) is placed on the mantap and rice in placed on the leaf and the thoranam arrangement is similar to the one used for Varalakshmi Pooja.
OHP sheet toran or thoranam - Craft ideas for festival decoration at home
Traditional maavilai thoranam is more important that the artificial thoranam or thoran we make as a craft. Oraganize mango leaves of almost similar length as shown in the photo. Then using a pair of scissors cut the stalks. Then as shown in the second photo,fold the leaves around a string and staple them so that we get a toran with all elements of equal length. A quick and easy way to make a mango leaf thoranam unlike the traditional method of making thoranam where we use the stalk to pierce the leaf so that it holds on to the string. This may considered to be a modern and sophisticated method of making a thoranam
Though ready made thoranam made from coconut fronds are available the video in my channel Rangolisansdots for those who want try at least once - how to make a thoranam
Simple kolam with dots for Pillayar Chaturthi or Vinayaka Chathurti
Another simple rangoli design with 4 dots to 1 dot grid can also be drawn in the Puja Mandapam. This rangoli evolves from the basic shank or conch design as seen from the images below. We can decorate the rangoli further with few more patterns
Turmeric is applied to the garland at the narrow areas. A 21 ball cotton garland is used.Again we can recite slokas or songs according to our customs.(Where one does not get banana leaf, mango leaves etc. replicas may be used) Offerings to the main idol include fruits - bananas, wood apple, sugarcane, corn, coconut, betel leaves and nuts, kheer or payasam amavadai and of course kozhukattai and modhakam.
How to make kozhukattai
Ganesh Chaturthi Naivedyam recipe
Simple decoration for Ganesh Chathurthi
Some kolam and other decoration ideas that may be useful for celebration of Ganesha Chathurti are at
Vinayakar Chaturthi kolam and decoration
Rangoli for Puja room