The coastal route looks simple enough, basically you get on flight following, tell them what you’re doing, and follow a VOR radial in then another one out?
Yup...You enter Bravo from the north at 5,550' on the LAX 323 radial overfly the LAX VOR then leave the LAX VOR on the 123. Super simple, even simpler if you are /G. I have all the routes saved in Foreflight as favorites as well.
You are expected to enter and exit the Bravo shelves on those radials fully flying the whole route, no cutting corners...it can happen, but don't expect it or ask for anything else being unfamiliar.
From SBA, pick up FF and climb for 5500'. You will get handed off from SBA Approach, then Magoo Approach then SoCal. Do not bother with any Bravo requests till your first SoCal handoff...which will be pretty close to the Bravo but just keep navigating towards the entry point. All you need at the first SoCal handoff is "SoCal, Skylane 12345 Level 5,500....request Coastal Route". Done. You may get "expect coastal route", "on request", or even nothing...but as long as you do not get "remain clear of Bravo" or are not an unsure bumbling fool on the radio (which I have heard) you can expect that clearance will come. Be forewarned, they sometimes do not issue that actual clearance till you are face to face with that blue line but it will eventually come. Once in a blue moon I have to query ATC "Confirming Bravo Clearance?" at the last second but they are generally pretty good at getting it to ya.
Once you get that clearance it is on you to follow and fly the published procedure. They will not vector you in Bravo except for other traffic. Easy peasy.
Many advocate for the SFRA for one reason or another but I am not a fan as you have to leave FF, self announce in the SFRA then try and re-establish FF on the other side again with a new squawk in pretty busy airspace. If the SFRA is open, I have never been denied another route and can remain on FF the whole time. SoCal WANTS to be talking to ya and rarely denies FF or a published Bravo Transition weather permitting if prepared and competent, but if you prefer not to talk it is certainly an option.