By Jason McDonald When you think of retirement, you may think of spending your days at home, whether it's watching TV, talking to family and friends, and anything else that may be considered relaxing. It can be difficult to retire, as the likes of Robert Jain will agree, but this doesn't mean that this must lead to a period of unproductiveness. Older retirees can still contribute if they please. Here are 4 of the best ways that this can be done. Retirees can stay productive in a number of ways, including picking up and developing new hobbies....