Make-ahead tips for Holiday baking?

Incidentally, most cookies taste much better after the dough has been sitting in the fridge for a few days, whether or not you're cooking ahead due to time/schedule constraints. Some people say you should freeze dough with raw egg in it after two or three days. I buy very fresh local organic eggs, and I store the dough in the coldest place in my fridge, and have never had a problem when I've stretched that fridge time to five or six days. ;o)

Ditto on the butter/shortbread cookie dough that you can freeze ahead. You can also bake off a batch when you have time and keep them frozen. A friend of mine has done really well with baking her apple pie and freezing it, I bet chocolate mousse or cheesecake tarts would do well with freezing 1-2 weeks ahead. Spice, tea blends, and cookie/bar ingredients in a jar also make great time friendly gifts.

Sadassa-Ulna reminded me of another tip. When freezing or refrigerating (even just chilling!!) any dough that will eventually be rolled into balls (including nut crescents, which start as a ball when I make them), roll it into a log before wrapping tightly. Then, when you make the cookies, simply cut off a squarish piece and you're just a few strokes from having a round ball. The log's diameter should be figured accordingly. Also, I keep sanding sugar and similar decorative materials in small flat deli containers with lids, to reuse throughout the baking "season." I often use them for pre-measured ingredients like raisins, chopped nuts, dried fruits, too (night-before activities, generally). They stack so nicely! You can buy them quite reasonably at places that sell to restaurants. The pint-sized ones work well for freezing cooked legumes and grains, so I love having them on hand. I make citrus scented sugars over the Thanksgiving weekend, too. When making truffles, you can chill unshaped blobs of the mixture on a parchment lined cookie sheet quickly in your freezer (or in your fridge). That makes it so much easier to roll them. Truffles and rum/bourbon balls hold very well in an airtight container -- I use small metal cookie tins -- so I almost always make them over Thanksgiving weekend. (My boxes typically go within a week or so of the Monday after Thanksgiving.) ;o)

It seems to me major grocery stores have sales on baking items well before Thanksgiving, so around this time of year I pick up good quality ingredients like nuts, chocolate chips, spices, and unsalted butter (which can be frozen). I like to make double or triple batches of cookie doughs and freeze them, sometimes rolling them into appropriate size logs for slicing.
I also start looking for the type of container or plate I want to give out; I also buy rolls of food grade cellophane at craft stores. And I make lists of who will get what, etc., i.e. some people get more of their favorites.
One thing I once read about, that I kind of do, is mix dough types up in succession according to flavor so that I don't need to wash the mixing bowl. So I might mix up a choc chip dough, then after scraping out the dough I'll make pecan fingers, then peanut butter. I don't need to clean out the bowl because it's OK if tiny particles of the first get into the second and same for the second into the third (but I wouldn't make a strong flavored or dark cookie and then a mild or light colored one without washing the bowl).

Start your planning now. That means: select recipes, organize them so you can easily find them when you need them, make lists of special ingredients (or the not-so-special ingredients like flour and sugar that you'll use a lot) and start shopping for them now. Develop a timetable, as to when you're going to bake what. Make all different kinds of cookie doughs on the same day, measuring dry ingredients for all of them at the same time (I use sticky notes to label what's what), and only clean bowls out that absolutely need it during your dough making marathon. (Use your judgment on this one. A bowl that you've just used to make a neutral dough like sugar cookies or nut crescents can be used for another batch of cookies without washing.) When you put on your calendar the dates you'll be making various things, ask yourself if you need to freeze butter, bring anything to room temperature, etc. before you begin the project; then, calendar those tasks, too! (Almost all of my baking is done "around the edges" of my busy law practice, with December being my busiest deal month many years, so I've learned this one the hard way.) If you're sending gifts of baked goods, make sure you have all of the shipping materials you need before Thanksgiving. You can write address labels during that weekend or otherwise well in advance, too. There was another Hotline question recently about making gifts in advance: http://www.food52.com/hotline/16920-holiday-food-gifts where I provided more information along these lines. This is all just off the top of my head. I'll add more later. ;o)

Some cookies (spice, Lebkuchen, Springerle) should be baked ahead so they can develop the full range of flavors. We always baked these three recipes the weekend after Thanksgiving, which was a great head start.

I agree with Kenzi, I always make batch after batch of cookie dough wrap it well and freeze. Makes my life so much easier. I also make pie dough about a week before I am going to make pies wrap that well and freeze it also. I like to always keep these in my freezer around the hoidays,

Freezing dough is the way to go! (And, it rhymes.)
I generally think that pre-made mixes of dry ingredients are a little fussy for way ahead of time, but it's something I definitely do the day before a big holiday feast tornado is about to hit.