Sat for the AWS CP-F exam today and passed. Not sure of my score yet. I am still waiting for my results email.
I used the following for preparation:
ACloudGuru course & practice exam which I took about 5-6 times
Whizlabs Practice Exams - took all 3 about 5 times each
AWS Best Practices papers
I kept taking the practice exams until I got 95% or better and spent more time reading the questions and mentally reasoning off all right and wrong answers, making sure I understood why the answers were correct.
Lastly I would say I saw 7-10 questions from the practice exams on Whizlabs. There were questions about info not covered on Whizlabs or ACloudGuru like AWS X-Ray and AWS Opsworks.
One thing I will say is Whizlabs definitely did a lot for my confidence. Seeing that I did know the material by taking the tests helped.
Now I start preparing for the Solutions Architect-Associate exam