Generally you just place the bearings in the headtube, nothing more.
If you use the cheap chinese headsets from aliexpress or the one who came with your frame, they are disposable parts.
Once they start to crack or aren't smooth anymore, just change them for about $10.
The bottom bearing is generally the first to fail/rust.
You can try to re-regrease the bearings too.
Mine is creaking too for a couple of weeks now, and need to be changed(usually twice a year).
Once, I had some problems with a split crown race.
It wasn't tick enough to provide enough space between the headtube and fork.
Scrubbing the fork, creaking and giving some resistance to turn.
Putting a normal crown race (non-split) solved the issue.