For the plate armor profession, the biggest gain is undoubtedly forging+jewelry, but these two are too expensive. Frankly speaking, it is not bad to choose mining and jewelry. If the cloth is exported, it is engineering+tailoring or jewelry. Physical output can choose jewelry+enchantment or engineering. For treatment, you can choose gold jewelry and the like.
Jewelry is the most profitable for any profession, but it is also the most expensive, so if the economic strength is average, it is ok to settle for the second best, and the major should be based on your own situation. For example, if you are an explosive mage and like to make copies, you will undoubtedly use the tailor's cloak to enchant and project acceleration gloves. If you are a priest and like playing the arena, you should consider practicing mining in order to survive. In fact, the professional income is relatively average, and the difference will not be too much. There is no NB major, only the one that suits you best.