I'm a 48 Shield Miller, so I need to be able to soak up a lot of damage.
There are two popular options with SM in terms of accessories.
The one I'm using right now is all beginners rings and amulets. You get a massive HP and FP increase and a decent amount of elemental resistance so you can suck up plenty of damage.
The other option is two beginners amulets and 2 perfect rings (20% attack, 25% defence) with the thinking there being that if you get hit less, you don't need as much HP and get an added attack bonus as well. Bit expensive though.