When I was learning Japanese I found myself doing something that I think could be quite useful for other learners of a second language, and I wish to share it here.

Noticing the characteristics of your target language is an important condition in mastering it. One way you can do that? When you have enough exposure to another speaker of your target language, try and imitate them whenever speaking in that language. I don't mean be rude about it, but you should try and imitate the intricacies of their speaking. This helps you notice a number of things, such as tone, words used, and also other things like body language. It also puts you on a faster path to thinking, and then speaking fluently in that language.

One problem of this would be someone with a different standing in society as you, for example a member of the opposite sex, or someone who is in a different age group to you. It can come off as very strange if you start talking like someone such as this, which could get in the way of your progress, so it helps to choose someone similar to you, or someone who sounds like what you want to sound like.