I try to work on my short game at the range when the need arises.  This seems to be a weakness at times and this is an area my pro has worked with me the most on.  I play in a senior men's league which is comprised mainly of retired gentlemen, three days a week and living along the coast of South Carolina we play pretty much the year round.  So if I do need to work any part or parts of my game I go see my head pro who is a Master Instructor.  We have three teaching pros at our municipal course we can turn to and it is best to get professional assistance who the game goes south or needs a tune-up.     

After my round today, it appears that I need to work on my putting.  Every putt seemed to break right today.  Had numerous birdie putts inside ten feet today as well as an eagle putt and I just could not have any luck.  Great stroke and distance, they just would not hold their line.  Shot 74 but felt like a bridesmaid.  Have to admit that the greens were a bit slow and seemed as though they had not been mowed due to all the rain.   Life is good and should be happy with my score.  But this is golf. 

Living in Switzerland I work on my fitness in the off season.

Also I try to practice putting all few days on the carpet

Putting is my biggest off season effort.  I am really concentrating on any putt from 6' in.  That seems to be the biggest source of my scoring woe's this past year.  Also the entire putting stroke needed some fine tuning.  

I'm in Indiana and we can have as long as a 5 month layoff some winters.  I have never done much swing wise over the winter.  I refuse to hit into a net so I just practice putting inside now and then.  I also have all my clubs checked each winter for loft & lie and re-grip if needed.