Template monster is the oldest place to place your template. there are a great varieties of templates and you can place your template there.
You will get the most control of your template in GrameenTheme. This site is made for developers and designers. you will get maximum benefit from this website. so, register with GrameenTheme.
you can place your templates in themeforest. it has a great user base and gives a percentage of your product sell.
See the book OpenCart 1.4 Template Design Cookbook.
See the book Joomla Mobile Development Beginners Guide
List of my works:
- Product Based Quantity Wise Shipping: Find it here.
- OpenSSLCOMMERZ: integrate SSLCOMMERZ with opencart: Find it here.
- Fine Search v.1.0 - Improves Opencart search feature to find relevant: Find it here.
- Opensweetcaptcha - An easy way to generate attractive captcha for your system!: Find it here.
- Custom Field Product - add unlimited custom fields to the product form: Find it here.
- Formcaptcha - add captcha on the register page: Find it here.