I cleared my plab 1 exam in first attempt Alhamdullilah.
My sources were plabable and plab 1 keys and OHCM.
Duration of preparation was 4 to 5 months as i am a mother to an infant and cant give my full time to studies.
In my opinion plabable is sufficient to pass plab 1as it covers all topics. You don’t have to cram the answers try to understand the topic and concept.
As you go through a chapter make your own notes i am saying again make your own notes from plabable and plab 1 key explainations. And go through them again and again. They are really helpful for revision as well. Try doing all mocks of plabable after you think you are fully prepared.
Best of luck to future candidates.