During that time I think about what it is that I really want to be doing. After a while I automatically skip to this step without having the desire to refresh HN.
To the point that I sometimes do it in the middle of talking to people (while sitting behind my desk), who will point it out to me, and then I will close the tab. And then re-open it a few seconds later while still talking to them. ctrl-T O enter, for old.reddit.com. It's really a true habit.
There is an extension where you can limit the number of tabs you have open, I'm going to try that again. Limiting myself to 1 should lead to some conscious thought, after those keystrokes fail a few times.