Do you pressure test the system then dye test? or the other way around?

depends on what information i can gather from the customer. leaks all the time or only when pump is on. you have to play detection and interviewer at the same time to determine what course of action you will persue.

I usually dye test first

For me it also depends on the season. When the water gets down to 38 degrees I will always test piping first, skimmer and structure as far as I can reach from the deck, light etc.. If I find nothing I'll set up a bucket test for 24hrs to see the size of leak I'm looking for then dive in. The more info you can gather from homeowner or service guy the better. If it leaks more while pump running you should be suspicious of return line piping or a crack in the spa structure(if attached) that is below water level when pump is off and rises to overflow into pool when pump is on.