Cross-browser compatibility sucks. Even with the best testing, end users will likely still find bugs.
Would you like your developer to fix those bugs? Read on.
1. Screenshot the Issue
This is important. Screen shot what’s going on in your browser window. Screenshots eliminate a lot of confusion and will show exactly what the issue it. You can even go one step further and highlight the issue sections with a little [insert microsoft paint-like software here] magic.
Just to review, you can screen shot on Windows (and most Linux machines) with the Print Screen button. You may need to paste the image copied with print screen into your favorite image editor then save it. On a mac, you can use
Cmd + Shift + 3 to capture the entire active screen or
Cmd + Shift + 4 to grab part of it.
2. Describe the Expected or Desired Behavior
So somethings wrong, we know what it is and can see it (see step one). What was supposed to happen? What was it supposed to look like?
Include that information. This is important. Your idea as an end user might not be something your developer(s) accounted for. So include what you expected to happen or how you expected the page to look.
3. Include the Relevant Browser and Operating System Info
In your bug report include the browser (or email client, depending on the project) that you’re using along with its version. Also include what operating system you’re using and its version (eg. Windows 7 SP1, OSX 10.8.2, or iOS 6). These help developers reproduce the bug with is extremely important to finding a solution to the issue.