Big disclaimer: it is NOT a good idea to be full tank before end-game (220+) as big tanks are really hard to level (even with a group, but there are ways if you got the friends) and aren't as necessary for most bosses.
However, it is not a bad style to play a slightly tanky hybrid (which is what most of the following will apply to).
(Edit: for the extensive full-tank guide I recommend clicking
here)
The big one I see missing straight off is protective stance. You can only have stance or frenzy so you do have to sacrifice that, but it's free armor added and a must-have skill for any tanky build (max skill points).
If you hybrid you want your offensive skills to be (in order): rupture, pummel, double attack, giant-swing (max points in order except dbl att; just enough to hurt 10 levels above you) (note: most hybrids use ax-offhand over shield so I dropped shield-bash in favor of giant-swing, otherwise same as above)
If you don't ever have a good druid on hand and struggle get a bunny (#bestTankPet). (and even for leveling; it has heals and energy regen that means fewer deaths, faster skills, fewer lixs/pots, more fun)