If someone were to research as soon as something finished, it doesn't matter what order they do them in. If you do a single line first or do a single trait on each first, the amount of time required is still the same. What does matter is how quickly you get your total traits up if you're crafting your own gear. If you want the most traits in the least amount of time, you simply rotate which you're training equally. It's also best to choose traits that appeal to you more. Divines (armor), Sharpened (weapons), etc. should be prioritized after something you don't expect to use soon.
There are multiple addons that track completed research and active research, such as
CraftStore.