Get rid of all the excess stuff that has accumulated in every nook and cranny. Put it in storage or give it to a friend.
People need to be able to envisage what the property would look like if they were living there. People often find this difficult, so make it easy for them to see all the fantastic living space you're offering them.
Don't make it look like a generic hotel; leave some personality. Apart from anything else it gives unimaginative buyers suggestions as to what they might do.
People are often buying into a lifestyle as much as a property. Show them the attractive side of your lifestyle.
Consider removing any bulky furniture that makes the room feel small and replacing it with smaller furniture.