Most tanks swear by outfitter – a tool that allows you to quickly change around pre-saved outfits. For instance, say I'm going to be tanking the nature phase of Hydross. Before even setting foot in SSC, I would have spent an hour or so making sure I had all the necessary gear, stats, and configurations that Hydross requires. A good part of this time would be spent getting all those gearing changes into an easy to use outfitter profile – so I would just have to click one button to wear the gear.
Of course, that's resistant gear and it's expected that there'll have to be a bunch of switching of it. However, the gear switching doesn't end there.