なく vs. なくて and stem form vs. てform as conjunctions

I have been wondering about this, since every time I hand in a 作文 in a Japanese class, I'm corrected on conjunctions. It seems to me that whenever I use a てform as a conjunction, a response comes back that it has a cause-and-effect feel. I thought that it was just neutral, since there are so many different ways to express cause and effect, but it seems that might not actually be the case. That being said, I thought that stem forms and なく might be the actually neutral way to join two clauses. I just wanted to know if I'm correct.