I suggest going with a heavy CDR rune focus and full tank masteries. I Max W first, followed by E. focus on ganking and becoming a walking wall. You can soak a lot of dmg with the Max rank/spam W and get out of tough spots with E. It also makes for a great engage tool with the shortened cd when you hit champs. Your Q will be trash dmg but still zones well and works as a slow for chasing enemies down. I typically build cinder, Mogs, thornmail, and spirit Vis. From there, itemize for the situation. Do you need more armor, MR, engage? You can get randuins, abyssal, or whatever that catalyst item is that speeds up the team, cant remember at the moment.
It's worked well for me. Understand however, that as a complete tank, you aren't completely able to carry the way you might on heavier dmg champs. That being said, if you have any level of competence on your team, they will get the job done while you're soaking up 4 champs worth of dmg. I've had pretty good results as a mid-lvl plat player. I may or may not get to D5 this season so there are probably higher level players who have guides posted somewhere.