Oft times in the life of a writer the dreaded condition of writer's block will arise in various forms of severity. From a mild "I don't know what happens next in the plot" kind of writers block to a complete "I can't write" author shut down.
It's my opinion that when we get stuck in repetitive patterns our minds are no longer stimulated, thus creativity diminishes. This can lead to writer's block, or perhaps to sub-par writing.
Routine is important, without it we would never get anything done! I'm not dissing routine here. What I am advising though is to go out of your comfort zone once in a while. Switch things up a little. If your usual hangout over weekends is the sofa at home, then take the time to meet some people in a park, club, bar, book launch, movies...the list is endless. Try experiencing new things and new sensations. If you have never been on a roller-coaster, now is the time to try it!
The change in routine and the stimulus of new experiences will definitely spark your creative side that leads to better writing.