I've chosen an album that holds 6x4 photos as my 'album' rather than a scrapbook style album. I have used this 'mini album' idea a few times, but mainly with a single 6x4 per page, as opposed to double (2 landscape 6x4s on each page), which I decided in this case.
The idea is that I will be able to print off my photos and slip them into the album directly, while adding in 6x4 journalling cards. The double size allows me to rip the seam between and also include some 'layouts' which would be a 6x8 size. This is all theoretical so far though, as I haven't started! I'm just trying to pick the easiest format possible, before I start. For now, it's about picking things to document, collecting daily life bits and pieces and taking lots of photos.
I'm hoping this will make a great project to look back on in e.g. 10 years time to see how we really 'lived'. Ali also tends to do this every year and stores all her layouts in one large album.