Start with a table like this and see if you can actually use the elements: campaignmonitor.com/css
From experience, table layouts with inline styles (yuck!) seems to be the only thing that works well across all email clients. I don't know if it has improved over the last couple of years.
To answer your question, if you want to test it across all email clients, you'll just need to physically test it across all email clients you have access to and judge if it looks ok or not.