Is 再过［时间］ the most common way of expressing "in [amount of time], something will happen"? I ask after encountering the following sentence in Tatoeba: 


  再过两、三个月，你就能说得一口流利的英语了。
Yes, your guess is right. However, I think you should focus on the character "再" here. There are several such patterns with "再". 

The pattern "再 + verb + [], [] + 就 + []" is used to express a condition, a premise; remember that "过" here means "[time, etc] to pass, to elapse" and "再" means "to continue to do something" or "to do something again" here. This pattern is somewhat like the pattern "if sb/sth continues to do sth,sb/sth will..." in English.


  再向前走500米，你就会看见那栋建筑。 [if you ]continue to go forward for 500 meters, you will see that building. 


"再" here implies "you" have covered a distance already, so now you continue to walk.


  再写一个小时我就去睡觉。 [I want to ]continue to write for 1 hour, then I will go to bed. 


"再" here implies "I" have written for a while, so I want to continue to write.


  再骚扰我，我就报警。 Warning: I will call the police if [you] continue to harass me. 


"再" here implies "you" have harassed me for some time, so now you continue to harass me or harass me again.

When a police officer is chasing a criminal, he would warn the criminal,


  再跑我就开枪了! I will shoot [if you continue to] run/escape.