If one of your new year's resolution is to provide more stimulation for your indoor kitty, leash training might be an option. I always advocate for kitty enclosures in the back or side yard but if you rent or live in a condo that might not be an option. In my experience, the more people friendly and treat oriented your kitty is the easier leash training will be. The most important point is to take it very slowly - get your kitty used to the harness or "walking jacket" inside for short periods of time before ever venturing out. Never push things if your cat is fearful and wants to hide. Kitty Walk strollers may be an option for a cat who likes to have some privacy but still look out and see the world. Have fun and let your best furry friend decide the process.