You just have to be yourself and answer truthfully! The same questions come up but worded differently and if you are not answering truthfully you can be caught out....The interview generally follows the personality test and they will check that your test profile result ties in with your persona at interview.
They can be tricky especially when you come across a question such as "I get frustrated when stuck in traffic jams" - just think about how you would USUALLY feel not necessarily ALWAYS feel and answer accordingly.
There are a few tests on the web you can practice on but I'm not sure how useful preparation is for these tests! Good luck
