My question so general, but I think the answer will be specific.
All I want to know is:
Is there a way or steps or mechanism to test the application (web application) in a professional way?
Many times when I finish developing and try my application, testing it with dummy data several times, and when I think every thing is okay and I think I have covered all possible scenarios, I find I forgot important issues, or others tell me they found problems in my application.
How do I overcome this problem, and save my time?