There are many techniques that can be used to improve the quality of software. Some of the most effective ones are:

1. Test Early and Often
   Testing should start as early as possible in the development process. Testing early helps catch defects early on when they are cheaper and easier to fix. Testing should be done continuously throughout the development lifecycle.

2. Perform Cross Browser and Cross Device Testing
   Testing your software on multiple browsers and devices is essential to ensure a good user experience. Using tools like BrowserStack, developers can test on thousands of browsers and real devices. This helps find compatibility issues and bugs.

3. Automate Tests Where Possible
   Automating tests helps run tests quickly and frequently. Automated tests can be run as part of your CI/CD pipeline. Some types of tests that can be automated are unit tests, integration tests, regression tests, etc. Automation reduces human error and improves coverage.

4. Have a Quality Management Plan
   Having a formal quality management plan outlines your software quality goals and objectives. It defines roles, responsibilities, processes, and metrics to measure quality. A quality plan provides guidance for testing and improvement efforts.

5. Do Formal Technical Reviews
   Conducting formal technical reviews with stakeholders helps catch logical and functional errors early. It also helps keep developers accountable. Preparing for and presenting in reviews improves the quality of code.

6. Use Ad hoc and Exploratory Testing
   Manual testing techniques like ad hoc and exploratory testing help test the usability and edge cases of your software. This helps find bugs that automated tests may miss.

7. Implement Continuous Integration and Delivery
   Integrating changes frequently and delivering changes quickly helps improve software quality. CI/CD enables fast feedback loops so issues are caught early before they propagate.

In summary, a combination of testing techniques - automated and manual, early and often, across different environments and platforms - can help you significantly improve the quality, performance and stability of your software. Automation, good processes and tools also play a big role in software quality improvement.