eso, esto, ese, este...
Does anyone have a clever way to remember that "eso" is "that" and "esto" is "this?"
Same for "ese" and "este?"
Well... the pattern is not that difficult: closer ones have a "t", like "esto" and "este", and the farther ones don't. They are word you'll be using all the time, so I wouldn't bother coming up with fancy mnemonic methods for remembering these. If you want to know, etymologically, the "t" in "this" and "esto" have a common ancestor (and so does "that", but never mind).
A little rhyme that I learned is "this and these both have T's". Of course this is a useful way of memorizing them in the beginning, but after awhile it becomes almost second nature to know which to use, although a dialouge such as this would be amusing:
A) ¿Cuál camiseta prefieres? B) Umm... umm, prefiero...sings rhyme under breathe ¡ah sí! ¡Prefiero esta camiseta!