ESA New Claim - best way PDF or call?

Hi! Thanks for the help of this brilliant site so far - it's really helped me to feel that applying for PIP and ESA are not only appropriate for me, but has given me confidence around the process...

I called the DWP to start a claim for PIP today, which was quite easy following your advice on what info to have ready...

I intend to apply for ESA also. I didn't call today to start a claim as I don't currently have a Fit Note, even though I've been ill and struggling for several years - I've been self-employed and therefore have never needed one. I am waiting for one of the GPs to call me back about getting one issued...

i wanted to ask, I saw you could either start a new ESA claim with a call, or fill in a PDF / paper form and take it to a Jobcentre Plus. Could I go ahead and start a claim with a call if I don't have a fit note? Or could I start filling in the PDF form in preparation to claim and add the fit note details as I get them? Is the claim process a lot slower if you don't start it by phone (generally)? What do people feel is best?

Thanks for your ongoing help!