#1 Send the same proposal to several universities
A good proposal needs to explain why you want to do your research at a particular university. That's a big part of the feasibility (the fit between project, person and place) and methodology (how are you going to use this university's equipment and archives; when and where will you need to travel).
It's OK to apply to more than one university in parallel, but, in that case, you're writing research proposals.
#2 Use online proposal templates (without evaluating them first!)
It can be tempting to search for PhD proposal samples on the internet, but make sure you evaluate what you find. Some websites may host old proposals from previous PhD students, but there's no way of knowing how relevant these are to your subject and university – or if they were even successful! More 'generic' research proposal examples can offer guidance, but they won't be tailored to your specific project.
The best place to look for a PhD proposal sample is your university. Consider asking your supervisor if they can share a good proposal from a previous student in your subject – or put you in touch with a current student you can ask.
#3 Confuse the proposal with the PhD
We've covered this on the blog, but it's simple enough to include here too.
You're setting out to do a PhD, but you (probably!) haven't done one yet. So you don't need to include research findings, in-depth analysis or a comprehesive literature review. You need to make a case for the research and analysis you want to do.
#4 Ignore your university's help and guidance
The advice on this page is necessarily quite general. We're considering adding guides to writing PhD proposals in specific subjects in future but, for now, the best place to get specific advice for your academic field is probably the university you're applying to.
See if you can get some subject-specific tips by contacting a supervisor, or just checking with the admissions team for your department.
And remember: if they give you a structure and a word count, stick to it.