Apart from the obvious (getting 528 gear in LFR and/or 540 in Flex), you could farm
Burdens of Eternity in Timeless Isle to get 535 gear. I assume you already got the one that is given in the chest near Ordos. After that the drop rate is low but you should get several in 2-3 weeks. You can also buy some for 50k
Timeless Coins, or play the lottery in the
cave (500 coins to have a chance at a Burden, with partial refund if you fail).
On Timeless Isle, you should also try your luck twice a week, once with Ordos and once with a Celestial, using
Warforged Seals. Ordos can drop 559 gear. The Celestials drop 522 or 553 gear. The new raid group tool is ideal to find a group quickly for that.
If you have a blacksmith, or can get the help of one, you can craft a belt and leggings (both 553 ilvl).
You're only at chapter I for the legendary quest. It's tedious, but the cloak you get at the end
is worth it (608 ilvl, upgraded for free).
As long as your gear is in flux (changing often), don't bother too much with gems and enchants, especially since LFR and Flex are too easy to require heavy optimization. But if you really aim at SoO HM, you will definitely need to have your professions maxed out for the perks, and your stuff properly optimized. By the way, Enchanting is fine, but Tailoring is not... This profession doesn't give any useful perk for a tank. Since it's still low level, maybe you should reconsider this. Even Mining would be better (Stamina perk).
