Present simple or continuous

The Present Simple is used for:

• regular actions or events
  He plays tennis most weekends.
  
• facts
  The sun rises in the east.
• facts known about the future
  We leave at 8.30 next Monday
  
• thoughts and feelings about the time of speaking
  I don't feel very well.

The Present Continuous is used for:

• the time of speaking ('now')
  Shh, I'm trying to hear what they are saying .
• things which are true at the moment but not always
  We're looking for a new flat.
  
• present plans for the future
  We're having dinner with them next week .