I am seriously confused. xD

In sentences like: "For me it was great!" 「私は楽しかった。」right? But what if you want to use one of those 3 above ones...
I think 対してmeans 'opposite'. (彼は楽しくなかった, しかし彼に対して私は楽しかった。) correct?

sentences like: (*** = よって or とって)
私に***勉強が楽しい
私に***あの人が悪だと思う
私に***着物は桜色の方がいい
私に***描くのが好き

Sentences I made up my own, but I seriously don't know when to use よって and when とって. Comes よって from 寄る ? and とって from 取る ?
Thanks for all the help! >,-)/
-Mesqueeb

佐々木さん 慰謝料の請求でも 場合によっては恐喝になりますよ。

明日は私にとって大事な記念日です。

彼に対して気持ちが変わった。

How I look at it...

によって- depending on/according to (depending on the case this could be seen as a threat )

にとって- for/concerning (As in, this is a big day "for me".)

に対して- towards (as in the above sentence, "feelings 'towards' him changed")

Just a tip, although it is interesting knowing which kanji such grammar words come from it certainly doesn't help. Just like knowing the etymology/'meaning' for the words, "as" "for" "me" won't help you get the nuance of "As for me, I like men".

It can help sometimes, but most of the time it doesn't help. And as far as I know, they aren't commonly used anyway. Perhaps someone else can clarify that.

Anyway, rough translation. I always understood にとって as "As for me" or a much stronger, "私には”

where as によって comes from　因る。
And translates to something like 'according to', but that is the only nuance of it that I know/learnt. I had no idea によって and にとって could be similar in meaning.

There's also not really any easy explanation for any of those words you used, just like there's no easy explanations for words like "of" "as" "for" in English.

They're all used so much in Japanese that you'll get the hang of it after exposure to the word. It's not something that really "clicks" from a quick explanation.

The "Dictionary of Intermediate Japanese Grammar" has a fairly thorough section on によって/より if you are looking for some in depth explanations on it.