But I spent far longer than I "should" have, because I wrongfully just assumed no crossing lines - another common convention that was never stated but that just was too hard to ignore. I did try various diagonals trying to get to something similar to the linked solution before the "three long lines" approach, but didn't get there because of getting stuck on that.
I think a lot of the time the bigger problem than getting "creative" is to clear your head of all the unstated assumptions that are very easy to cling to without even realizing. A useful method can be to try solve a problem with fewer restrictions, and then add restrictions back in and see what solutions can be adapted - that makes it harder to get stuck considering rules that don't actually exist.