Have you tried volunteering for a charity shop? I work at a little charity shop for dementia support. I have an interest in the cognitive processes and biological functions, so I plan to try and link that in. You can also look at transferable skills, such as interpersonal skills. Universities will be looking for these types of skills as well as interest in the subject.
Also I've been to several talks about writing a personal statement for psychology, including one from Oxbridge admissions. Reading books is definitely useful, as you can incorporate this into your statement which shows a real interest. Just make sure you don't get caught out if they ask you about a book in an interview.