We had a very difficult August with both DD and DH hospitalised, for different things. (Both recovering and should be fine - but scary at the time.) Luckily the volunteering/shadowing/UKCAT were done during July, but the PS and possible self-guided tours have suffered.
I am therefore employing the same tactic, as I used with my son, who had no excuses. Which is to write a first draft. Then never look at it again.
The main aim was to ensure that the school were aware of anything that might be relevent. But I have also realised that DC have never written anything like this before, and obviously they feel everything is riding on it. Both got stuck, essentially, on the first paragraph. Indeed I found guidance I found on the Internet suggesting you start on the socond and leaving the first till last.
Its actually quite easy to write something basic, at least for somone else. You don't have the same level of emotional investment. Four paras, starting with the why, adding some evidence, and then ending with the EC. Gaps to fill in the detail of reading etc and bullet points if need be. DS was horrified (honestly by then writing something was a lot easier than continuing the nagging) and immediately set about personalising it. But at least I knew the content was there. There were further edits from school, and he claims not a single word I wrote remained in the final version. That is good. At least I got him started.
DD is even further behind the curve, but only told me the school's deadline for a first draft was the next day, at 10.00pm. She eventually submitted her first couple of sentences and my "passionless" outline and bullet points. At least I know the school have all the material, and she will have learnt an important adult lesson, which is if you have something difficult to write, just get something down and then review. Editing is always easier.
Another tip then for scientists, is to find a friend who is naturally good at writing. A friend's DD has apparently already written half a dozen PSs, though still has her own to do...