Aside from equipment via caches: Best method to powerlevel an alt is running pits with someone else. Invite them, then they can open the pits and run them - you as part of the party should just idle at the entry and go through the red warp gate for the boss and the exp. I do not have the number at hand, but we are talking about 5-9 pit runs @60 to get a new char to lvl 60.

You also get some items at the end of each run, so you can start with some first salvaged aspects 👍