In Riverside County, hair salons are allowed to re-open, but not for "services that require touching of the customer’s face, such as facials, eyelash
adjustments, eyebrow waxing and threading." @RivCoInfo https://www.rivcoph.org/Portals/0/Documents/CoronaVirus/May/News/5.26.20_hair_salons_news_release_2.pdf?ver=2020-05-26-171857-070&timestamp=1590538773739

In @CountyofLA, nail salons, hair salons and barbershops must stay closed. http://publichealth.lacounty.gov/media/Coronavi …

In San Bernardino County, hair salons and barbershops are open, nail salons are closed. @SBCounty http://wp.sbcounty.gov/cao/countywire/?p=7205

And after much confusion and fruitless searching online, a spokesperson for @OCGovCA told me that hair salons and barbershops are open in Orange County, but nail salons are closed.

In @CountyVentura, hair salons and barbershops are open. https://www.vcemergency.com/vc-reopens 

In Santa Barbara County, hair salons and barbershops are open, but waxing, threading or other services that "cannot be performed with a face covering" are not allowed. @countyofsb http://countyofsb.org/uploadedFiles/phd/PROGRAMS/Disease_Control/Corona/HOO%202020-8-3.pdf