If your web application has a page caching layer, you can prime the cache from within the Tugboat config file. This code snippet should get you started:
php: commands: build: # Warm the cache - "wget -e robots=off --quiet --page-requisites --delete-after --header \"Host: tugboat.qa\" http://localhost || /bin/true"
localhost will cause Tugboat to load the front page of your application.
page-requisites loads all images,
delete-after removes the downloaded assets to preserve disk space.