Let's start with a simple fact: most PhDs that run into trouble do so long before their final exam. If your supervisor thinks you have a genuine and original PhD that can stand up to examination... you probably do.
So, as scary as it may seem as you prepare for a PhD, the viva voce really isn't something you need to worry about yet.
The real pitfalls - the things that actually can scupper a PhD - are a lot less obvious. That's the problem with pits, after all: they can be hard to spot until you're teetering over the edge... or plummeting into them.
In this post, I'm going to try and help you avoid that. Think of the following advice as a set of metaphorical flags, planted firmly next to three of the bigger hazards that might lie hidden along your PhD journey.
Sticking with the metaphors: if one thing's certain to increase your chance of tumbling into holes in the ground, it's walking forward with a telescope held up to your eyes.
You won't generally see many people doing this in real life, but it's a lot more common for PhD students. Metaphorically speaking, I mean*.
At the beginning of a taught degree, you're probably focussing on your first modules, the upcoming classes for those modules, perhaps the coursework or other assessments looming at their conclusion.
At the beginning of a PhD you won't normally have any of those things. As a result, it's all too easy to focus exclusively on the end result: a finished PhD thesis.
This isn't a bad thing in and of itself (a finished PhD thesis is what you're here to produce, after all). But that finished thesis is still a fairly distant target at this point. And if you're focussing on it too exclusively, you run the risk of missing more immediate obstacles and opportunities (remember the telescope).
This can easily lead to you become disorientated and disilusioned. Without a set of checkpoints and shorter term goals, what should be a pathway through your PhD can look a lot more like a wilderness in which you don't really feel like you're researching a PhD at all. If things get bad enough, you might not be.
A PhD actually lends itself very well to structure and short-term goals. You just have to identify them.
Start by chatting with your supervisor. Set a timescale (and direction) for your literature review and work out what the next steps will be from there. Experiments, drafts, training, related projects: have an idea of what you want to achieve and roughly when.
Short-term goals will keep you moving and give your PhD a welcome sense of rhythm and routine.
As you go, mix in a few medium-term goals (chapter drafts, conference papers, etc). These can function as more significant checkpoints, allowing you to mark and measure your progress towards that finished thesis.
OK. So you've replaced the telescope with a map. But - at the risk of extending the metaphor further - a map is only as good as the route you can plot with it.
Short- and medium-term goals can help save your PhD from the research wilderness, but to do so they need form a pathway towards your ultimate destination: that finished thesis.
The fact is that not all of the tasks and objectives you encounter during a PhD will do that. Many do other useful things instead: developing new transferable skills, building professional experience and generally helping you get more from your doctorate.
These are rewarding and appealing tasks - particularly if paid teaching work or publication and presentation opportunities are on the table. But they won't necessarily contribute towards your actual thesis.
Taking on too many short-term commitments can quickly distract you from your overall goals.
It can be difficult to pass up opportunities during a PhD.
Let's say an academic contact invites you to contribute to a publication on a topic related to your specialism. You're not sure when that kind of opportunity will come around again, you don't want to disappoint your colleague and you know that getting published will be great for your CV once the PhD is complete.
The question is how much that extra writing task is going to detract from your current research or writing task.
Making that call can be challenging, but it's a valuable form of experience in its own right. After all, time management isn't just an important skill for your PhD: it's also key to academic and professional careers.
If in doubt, get your supervisor's view. They should know what the current object for your thesis is - and roughly how long additional task are really going to take.
Much of a PhD involves working independently and more or less alone.
If you're in the Arts or Humanities you'll probably spend a lot of time with a pile of books or other research materials, pulling together your thoughts and developing your ideas.
If you're in a STEM field you may have more fellow students working alongside you - in the same laboratory or workshop - but you'll each be primarily responsible for your own experiments, data and analysis.
Either way, you can find yourself feeling isolated, losing touch with your fellow students, your supervisor and, perhaps, your PhD.
The risk is greater if you're studying part-time and greater still if you're completing your PhD by distance learning. In such situations it's all too easy to lose a sense of context for your day-to-day work.
This can make it harder to maintain momentum and motivation. And it doesn't matter how good your map is if you're losing the enthusiasm to keep moving forward.
No matter how you're completing your PhD, extended periods out of touch with your university, supervisor or fellow researchers should be a warning sign. Don't miss that warning sign simply because you've assumed that this is 'what a PhD is like'. It isn't.
A good supervisor should make sure you don't go 'off the radar', but don't rely entirely on them to do that. Supervisors are busy people and you may inadvertantly have given them the impression that all is proceeding well with your current PhD work. If that's not the case and things aren't progressing, be honest and drop them an email.
More generally, be on the lookout for 'networking' opportunities with your peers. Chatting to other researchers is part of what makes a PhD enjoyable and rewarding. It's also a nice way of reflecting on your work outside the more formal supervision and feedback process.
There's a chance your university or department will host some postgraduate research networks or 'reading groups'. If it doesn't, or you're too far away to make use of them, look for online alternatives. There are some friendly communities out there - including our own postgraduate forum.