The first thing you need to be aware of is what your target audience is.
A professional software developer already knows how to make your PC faster by installing the right device drivers, while a home user can't get much out of reading your in-depth analysis of Clang vs. GCC. An IT manager doesn't want to know which is the best graphic card for playing Battlefield 4, while a gamer isn't interested much in your cost-benefit analysis of virtualizing Linux servers on IBM mainframes.
When you aren't sure, ask your superiors what target audience they are aiming for.
After you found out who your target audience is, you need to find out what they want to read about.
- What's new? Any brand-new technology your audience might want to use is always worth writing about. Tell them what it can do what their current technology can't, how to do this, and why they should (or should not) buy it.
- What's popular? What are the technologies your target audience uses daily? What tips can you give them about how to make more out of them? Any technical details they might be interested in?
- What's unpopular? Which are the main issues and annoyances your target audience faces daily and what advise can you give them about how to solve these issues?