1. Explain it simply
State the cause first, then use 因此 to introduce the result that follows from it.
Order: Clause A，因此 Clause B. 因此 opens the second, result clause.
因此 is more formal and written than 所以, and it fits reasoned or factual results.
因此 does not pair with 因为 - use it on its own, and keep it at the head of the result clause.
2. Show examples
昨天下雨了，因此比赛推迟了。
Zuótiān xiàyǔ le, yīncǐ bǐsài tuīchí le.
It rained yesterday, so the match was postponed.
因此 opens the result clause
他准备得很充分，因此考得很好。
Tā zhǔnbèi de hěn chōngfèn, yīncǐ kǎo de hěn hǎo.
He prepared thoroughly, so he did well on the exam.
the result follows from the cause
路上堵车了，因此我们迟到了。
Lùshang dǔchē le, yīncǐ wǒmen chídào le.
There was a traffic jam, so we were late.
因此 heads the second clause
3. Share a tip
因此 sounds more formal than 所以; keep it out of the first clause and off the very front of the sentence.