You should get the level 50 MH tool from the class quest. Beyond that, its up to you.

You may not be able to HQ them, but things like Twinthread and Darksteel Nuggets, and Rose Gold Nuggets, are your targets to grind out through 50 to 51 on. Once you hit 51, consider the crafted level 51 set (left side gear; the right side jewelry is going to range from 52 to 55). The penalty for being below recipe level is fairly severe in Heavensward, so try not to level too high before being able to make any refined materials.

I'm not saying I remember the numbers exactly, but I went from something like 70 Progress on a CS2 at level 50 to 190 Progress on a CS2 on that same recipe, at level 51, without any gear changes. Just removing that penalty more than doubled the Progress I was getting.