I figured this was the best place to post this, sorry if it's not.

I work in Photoshop CS2 if I do anything art related, and I've found some interesting idea on generating random map bases - the clouds / fill 50% hardmix thing is quite nice, it's usually what I use. The thing is, that if I try and do this I seem to never end up with the singular large landscapes that are always shown in the screenshots, rather I end up with a whole giant mess of islands or an odd sprawling spidery landscape that isn't very nice. I'm really not sure what I'm doing wrong.

Is it best to start with a very small document and then enlarge it - if so, does anyone have a recommended size?
Or is any size good and it's simply a matter of gettign the right settings?

Cheers in advance.