Applying for PIP

Hi everyone, I’m about to apply for PIP and was wondering if anyone can give me any pointers when filling out the form? I have RRMS and although I am not too badly affected yet I want to claim eeverything I am entitled to. From what I’ve read, it’s quite common to be refused this benefit then have to appeal. I would like to avoid having to appeal so if anyone has any advice on how best to fill out te form that would be much appreciated. Thanks in advance Lisa xx