Thanks! Now I don't think I will be using books for a reeeeeally long time....
You can use linking books to get to and from the nether, twilight forest, and End. That's just the book by itself cycled through your crafting square.
It'll take you to precisely where you were standing when you made it, assuming you are in another age. Use a Bookstand to put your linking books down in. So, for example, you make a linking book in your overworld base. You then travel to the nether, and make a linking book for the nether, put down a bookstand, and put the linking book for the overworld in that bookstand. Then, you can use the book on the bookstand to get back to your Overworld base. Now put the nether linking book in a bookstand in your overworld base.
Congratulations, you no longer need a nether portal to get back and forth! Rinse, wash, repeat for Twilight Forest and End.
Furthermore, you can create a Nexus so that you can, for example, go from Base A in the Overworld to the Nether, to Base B, which is in the Overworld some several thousand blocks away.
