This userscript provided me with TONS of extra exposure to katakana that made it much easier to lock into memory:
RE: シンツソ
シ・ン (shi・n) are entirely horizontal, like >
ツ・ソ (tsu・so) are entirely vertical, like V
Try writing them all, with this in mind
I’ve seen people complain that these characters are indistinguishable when handwritten, but seriously, it’s the difference between looking at > or V; No matter how sloppy someone’s handwriting is, the orientation should still be clear as day
Remember, English has d・b, and E・F.
If you can keep those straight, you can keep these straight, too!