My version of DD is my favorite scrap project of the year, Anne!
You need to (a) tweak it to what suits you best and (b) plan, plan, and plan some more before it officially starts.
I call my version of December Daily a Countdown to Christmas album because I run it from the day after Thanksgiving - Christmas Day and it's ONLY Christmas-related things (the two big differences from Ali's version). I'm a hardcore Christmas freak, so doing it this way makes the most sense to me and makes me the most excited to get it done.
As for planning/organizing, I keep a folder on my computer hard drive in December with all my fave Christmas things in it. I pull them all over from my EHD a few days beforehand knowing that there will also be some new kits coming out over the course of the first couple weeks that I will want to use, too. I also make a list ahead of time in Notepad that lists every day of the album e.g. Friday, November 28, etc. and then I will jot down whatever activities are already planned for a certain date. At the bottom of the file, I make a list of Christmas activities that can be done at any time during the season. This file also goes into my Christmas folder for my reference. While Ali recommends creating your pages ahead of time, I am too OCD for that, so I do choose a set of templates from one designer to use + my aforementioned folder of goodies, but that's it.
Lastly, you just have to COMMIT to the project. My PL ends when this album begins, and I do not do any other major scrapping during the month. Most designers (at least the ones I CT for) are only releasing holiday product, anyways, and then take some time off the closer we get to Christmas, so I don't fall behind on CT obligations, either. I don't let myself fall behind more than 3 days at a time and try to keep my pages more simple than complicated with an internal deadline that each page take no more than 60-90 minutes to complete. There's nothing better than having the album nearly complete by the time Christmas actually rolls around and then taking the next 7-10 days off of scrapping to enjoy the season.
I actually find AWITL a much more overwhelming project since it is so much more detail-oriented and supposedly encompassing all of the stories of your life in that week vs. capturing one story of your life per day in DD. I have done it in the past VERY simply by using Ali's templates and journaling sheets. I believe the last time I did it that I used some simple PL templates with little to no embellishments. If I was doing it paper or hybrid, I would include the journaling sheets from Ali (like she has done in her own album in the past) and not redo/scan them in.