The robes are crafted the same as regular armor except with purple wool. You can then dye the robes any color you like by combining the finished garments with dye. The witch/wizard hat will allow you to take on the effects of any potion you take while wearing it. So whenever you put that hat on it will apply the effect to you infinitely.
Creating bridges instantly over bodies or water/lava.
The wands are costly and require emeralds to make so use them wisely. But perhaps the costliest wand is the Wand of Death. It requires two additional Wither Skulls with an emerald but will kill enemies with one hit.