Print Toolkit HTML Template editing any good tips

I am working on creating a nice look for the page I am printing. The Print Toolkit seems to give me what I need but I’m looking for suggestions as to how best to create and edit my HTML.
What I want to do is use an external HTML editor so I get the look and feel how I want it and then upload that to my workflow step.
This seems to work ok and so far it seems to ‘keep’ the links to dynamic data … But it is all a little clunky - are there any gotchas to be aware of and does anyone have any good tips for doing this sort of thing?

Many Thanks