Hello mark and welcome.
I'm just about half way through mine. Only advice I can give is evidence, and plenty of it. As many photos as you can, preferably with you in them. Although apparently they prefer videos now. So if you can get someone to film you then all the better. Gather as much information for the unit you are doing. For example: risk assessments, method statements, product information etc.
Hope that helps and good luck
Regards
Sean