It's much easier to get up to Perry Aiken Flat from Leidy Canyon. The way is pretty clearly marked on the topo. With a 4x4 you can drive pretty far up. In fact I took my old Fork Maverick as far as an old rockslide that's only about ten minutes' walk below the 4x4 trailhead.
A short distance above the 4x4 trailhead follow the ramp-like jeep road to the left. It brings you to an open cowpasture with a corral with two gates. A good trail up to Perry Aiken Flat leaves from the uphill/smaller gate. This trail switchbacks up onto the ridge, then follows the whaleback ridge with moderate grades.
Near the upper treeline for Bristlecone Pines you can traverse left into the north branch of the north fork of Perry Aiken Creek, which is a cirque on the north side of White Mountain Peak at this elevation. There was ample water in this cirque when I was there in early summer. It's a great place to camp and explore, as well as a base for dayhikes up to White Mountain Peak via the dividing ridge between this cirque and the main north fork to the south. You can also backtrack to the whaleback ridge and follow it up to peak 13,9xx which is separated from WMP by a difficult knife-edge ridge.
Inyo-White Mountains