I had trouble remembering the difference between 辛 and 幸, until I started thinking of the extra line as a line of coke. With that, I can just say "one line of coke is all you need to bring you from a painful state to a state of happiness".
Also, with 喫, I prefer saying that "to enjoy a drink and a smoke is kinda like a contract with your mouth, because you provide your mouth with stuff to consume, and in return, your mouth transmits pleasing flavors to your brain. So it's kinda like a mutual agreement". Maybe it's just a preference of mine, but when I put it like that, I have a much easier time remembering it, because of the role the various keywords have in the sentence or something. Maybe my brain just interprets "with my mouth" as an unnecessary addition (since the sentence would have the same meaning without it) and decides to just forget that part.