I develop and maintain a number of sites for nonprofits. I recently set up a DreamHost account for a nonprofit and moved the Wordpress files, database to DH from another host. Everything is working fine; I updated the DNS servers to point to DH, can login to WP dashboard, the site is up (much more than at the previous host) and doesn't appear to have been hacked!
I have another nonprofit site that I want to redesign in WP. It's presently hosted on Yahoo Small Business using their SiteBuilder software. I want to host the site on DH eventually, but I need to design the site before I change the DNS servers to point to DH from Yahoo. Would I be better off setting up an add-on domain on the first nonprofit's account to design the site or setting up a new account and change the DNS servers later when the redesigned site is ready to go live?