During the very early phases of development in a Rails app, I prefer to modify the migrations files directly to add new columns (fields) to my tables (models) instead of piling
I run the following commands to solve this problem. Save it in a script and you are ready to go! Of course, this presumes that losing the data is fine. Loading the fixtures is easy enough to add to this script in any case.
#!/bin/sh
rake db:drop
rake db:create
rake db:migrate --trace
PS: My friend who gave me this idea calls this script rake_dance :)