The things you should do to improve your listening depend a lot on your current level. You cannot makeover your listening skills overnight, but steady efforts to train your ears can make a lot of difference! ETS actually has a quite comprehensive set of recommendations broken down by level, which are linked below.
|TOEFL Listening Skills||Low||Intermediate||High|
If you know roughly where you fall in this ETS chart, you should see their full set of recommendations! What follows below is a general set of recommendations to improve your reading skills. :)
Listen to as much as you can every day. You want to listen to all kinds of audio, from casual conversations to academic-style podcasts and radio. You will have all sorts of lectures and conversations to listen to on the TOEFL, and you want to be comfortable with any kind of audio!
Expand your vocabulary. Remember, the TOEFL tests your readiness for academic life, and it is important to increase your vocabulary on many subjects because you will have to listen to people talk about various topics at the university.
Get used to various native English accents. It can be easy to get used to just one or two accents, but you should get used to all kinds of speech: male and female voices; British, American, Canadian, Australian, etc. English accents; fast and slow speech; casual and formal speech. The more you are accustomed to, the easier it will be on test day.
Practice making a 15 second response to news or academic audio. Jot down or speak quickly a few key points you would want to make regarding something you just listened to. This will make responding to integrated tasks on the TOEFL much easier.