Building a successful Nopcommerce plugin is all about following best practices. Here are some tips to help you get started:

1. Choose the right plugin framework. There are many popular plugin frameworks available at https://nop-tech.com/, but it's important to choose one that fits your project's needs and doesn't require too much customization. The most popular frameworks include WordPress, Joomla!, and Magento.

2. Use established plugins as a starting point. Many successful Nopcommerce plugins were built on top of existing plugins that were well-known and reliable. This approach can save you time and money, since you won't have to develop the entire plugin from scratch.

3. Prepare your codebase carefully. Make sure your code is well organized and easy to read, and avoid using unnecessary code snippets or functions. This will make it easier for other developers to improve and maintain your plugin.

4. Test your plugin thoroughly. Before releasing it to the public, test it thoroughly on a range of different platforms (including both desktop and mobile devices). This will ensure that your plugin works as expected, and doesn't cause any unforeseen problems.

5. Document your plugin thoroughly. 

Designing a Reliable Plugin for Nopcommerce

When designing a plugin for Nopcommerce, it's important to keep in mind the platform's unique features and constraints. For example, plugins must be responsive and work on both desktop and mobile devices.

Additionally, plugins must be easy to install and use. In addition, it is recommended that plugins use standard WordPress features where possible. This way, users will have an easier time migrating to your plugin if they decide to switch platforms or browsers.