I actually took one picture of each of my children (mostly) once a week for an entire year. When I first heard about the idea, I thought it would be easy peasy. It seems easy. Just take a picture. I did attempt to make them different or new each week. That ended up being difficult because we have twin toddlers and we do a lot of the same stuff every weekend. Winter was harder because on the week days it's so dark that it's hard to get a good picture. And we tended to just "do" less than we do in the remaining seasons.
I considered a few options of what to do with all 104+ pictures I had. I ended up making a video. It was a nice return to working on creative things for myself after a fall of a lot of extra working my day job.
As for next year. I've missed a couple of weeks (even though I am now in the habit of taking pictures, so I have pictures to display). I'm thinking about doing a 52 portraits for their 4th year. They'll turn 3 on February 2nd, so I have a few more weeks to think about what exactly I want that to be. I was thinking it would be cool to try to take the same portrait each week for a year. Like standing in front of a wall in our house. That would be cool to see after a year, but I'm not convinced anyone (including me) would like to see the exact same picture every week. We'll see where those thoughts take me.