As said, experiment. Play around with the options. The worse thing you can do is have a fixed build. PvE is good for experimentation (PvP is not as forgiving), if you dont experiment you'll get bored very fast in this game.. ok not everyone does but i do

All kind of builds work in PvE, some worse, some better, but you can finish the game even with bad ones with a bit of luck.
Options (PickMe already named some):
/R for ... a pet!

Yup that's right. Why not have some fun? And it's not like you have to invest points into beastmastery
/Mo ..probably the best option for PvE, Mending Touch plus enchantments.
/E ..some enchantments can be fun i guess. PickMe suggested Wards, but avoid those because they are spells. In general, avoid non-enchant spells as much as you can.
/W ..WY as PickMe said, plus Protectors Strike when you get Zealous Vow elite (if you do)
/A ..when you get Lyssa avatar and daggers

This is a fun option, keep in mind that AoE scythe will usually do more dmg in PvE.
The point is really just having fun testing different stuff.