Right now we can only have two custom fields showing. I use the custom fields to show status of web pages ie. I have one for Copy, one for Images, one for SEO etc and I have a drop down 'not started', 'to do', 'in progress' 'with client', 'done'. It's great that the custom fields show on the cards but would like to be able to show more as quick reference. I set up a separate task for each page.