Title says most of it. How does one go about attaining a rod thats finely tuned to that plane? Particularily if you are in Sigil or some other major planar city. Some guild sell them? Have to go to the plane itself?
Just had a thought about scribing scrolls. From the SRD:
The creator must have prepared the spell to be scribed (or must know the spell, in the case of a sorcerer or bard) and must provide any material components or focuses the spell requires.
Well that becomes a problem and a blessing. If a scroll of Planeshift is only for one plane that means you can sorta hint where you want the PC's to go, it's a pain because you can only planeshift to that plane so if your outa saftey spells and all you have left is Planeshift to the abyss....well its sorta between a rock and a hard place
Our DM said that we'd need an item from the plane in question. Which meant that we needed to call up a creature from the plane in question and ask it politely to give us a hair. Which meant that we needed to know of a creature from the plane we were to visit. I think we ended up scrying for a relatively normal inhabitant of the plane, casting a communication spell through the scry, and asking it's name.