Practice by finding children's audio books slightly below your level. They speak clearly and advanced vocabulary will be given in context.
While doing this, you should focus carefully, try rephrasing (not translating) every few minutes.
Alternate this type of practice with radio programs, you should to this in a relaxed way, just trying to form a general impression. If its conversation skills you need, watch soap operas too and note body language and visual clues.
The best speakers/listeners are those confident enough to ask questions such a can you explain i dont understand the words