Mercury retrograde kicks in for December, so what are some good general rules to prepare? Take stock of what the retrograde will do for you personally, and research what are some positive ways you can make use of the energy (so see the house(s) being impacted, aspects he'll make, and how you can work with the energy). This is something you should do with every retrograde so you can emerge as unscathed as possible. Prepare yourself for the hard aspects especially, because these can be the most difficult to control. And know that while you can control your own actions and decisions, you can't control other people's, so try to have a LOT of extra patience.
Mercury retrograde likes to cause a lot of stress, so it's important with every Mercury retrograde to make sure you have an outlet for stress or some way to manage it that is healthy and positive. This tends to be what does all of us in. The stress alone slays us! So before it even begins, make sure you have a stress plan in place. If you get stressed out, what is something you can do right away to mitigate it? Come up with various ideas for various situations so you're prepared whether you're alone in your car, at work with your boss, or at home at a family dinner. It may be as simple as learning a breathing exercise.
Mercury is ruler of daily life, so we often get thrown off with the everyday stuff. Another way to prepare is to give yourself extra time for the things you know you'll have to do during Mercury retrograde. If you leave anything to the last minute, you have a much higher chance of that blowing up in your face. You can't do this for everything since there's always something that comes upon you fast, but the things you can prepare extra time for, you should.
Mercury is also ruler of health, so one of the ways I like to deal with Mercury retrograde is to do something good for my health during every Mercury retrograde. This can be an excellent time for routine maintenance and making sure you're on top of everything. I like to do a round of EFT during every Mercury retrograde to clear out the energetic sludge that builds up; whatever you're into, go for it, and you can use the retrograde as a reminder to get routine checkups and shots and such.
Routine maintenance doesn't have to apply to your health either - you can also use Mercury retrograde to do maintenance on your car (great reminder to get your oil changed!), your home (clean out your closets, garage, fix that hole in the shower floor), and your technology (clear out your inbox, organize your files).
Mercury Retrograde in Sagittarius: December 2017
January 2018 New & Full Moons
December 2017 New & Full Moons
Jupiter in Scorpio: October 2017 - November 2018
Saturn in Capricorn: December 2017 - March 2020, July - December 2020
Saturn in Sagittarius: December 2014 - June 2015, September 2015 - December 2017
Saturn in Sagittarius for Each Sign