1. Login to PrestaShop Admin.
2. Click on Products from Catalog tab.
3. Click on Add new product on the right corner.
4. Enter Name of the product and choose Enabled as Yes and click on Save and Stay. And all other fields are optional (Description, Short Description)
5. Go to Prices and enter any type of price you want.
6. Go to Associations of Add new vertical tab and assign a category from the Associated categories list.
7. Click on Save and Stay.
8. Go to Images. Click Add Files and select your Files and click Save and stay
9. Go to Combinations and click on New combination.
10. Select attribute Color and assign value, select attribute Size and assign value. After adding all combinations, click on Save and Stay.
11. Go to Quantities and add quantity to each combination.
12. Click on Designer Tool in vertical tab and set Product Customization as Yes.
13. Click on Save, the new product is added.