This is a precis of advice I'd give to NQTs or any younger/newer/prospective teachers based on my own experiences. I'm not entirely sure it's worth much but it was what I wanted to write about so I did.
1: Have another job before you are a teacher, at least for a bit. A real one on which your mortgage or rent depends, not a Saturday job. It will help you keep things in perspective. Some jobs are worse than teaching, some jobs are better. The time I did a 28 hour shift and got paid for 8 hours would be a particular highlight of my pre-teaching career. It still helps to remember that I had a much worse job once.
2: Learn quickly that you aren't Jesus. Don't carry the cross everyday. If you allow it, you will become the focal point for the suffering and pain of all your learners. If this is what you enjoy about the job, get a job in the pastoral system or learning support. Be approachable by all means, but get used to the fact you are a small cog in a wider support network.
3: Get used to the fact that some of your managers are fucking idiots. Hopefully not many, but some of them are. On the other hand some of them are fantastic and have an incredible amount of wisdom to give. As they don't wear badges marked 'fucking idiot' or 'sage' you'll have to work it out for yourself.
4: In a similar vein, if you have a poor manager, they will probably ask you to do about 45% of the department's jobs for them based on the fact that it's 'great career development' for you. This probably means 'no-one else will do it.' Very few of your managers really give a toss about your career development, they just see you as someone who hasn't yet learned to say no. Learn to say no. Your learners (which is why you do the job) will thank you for it.
5: Watch the Wire. At first you will think - why am I watching a programme on drug dealing in Baltimore, then one of the cops becomes a teacher and you get to see one of the most beautiful, painful, heart-breaking things you'll ever see. It will teach you that the system is stacked against some kids but that doesn't mean they can't be taught or are 'thick' - It won't teach you haw to get great SATs scores or brilliant exam results, but it might make you better at communicating.
6: On this note, so many teachers are very middle class. You probably are as well. Open your eyes to the wider world. It's really quite important to do this.
7: You are not Jesus (again). One of the best pieces I've ever had was from a head teacher who told me 'they just want you to know your stuff and do your job' - Occasionally you will get moments of visceral pleasure but largely it's a grind based on achieving learning objectives and keeping yourself (and them) on task.
8: Cynicism and criticism is not the same thing. Don't become cynical but retain your critical faculties. Some of the systems and strategies you will encounter in your career will be bilge. Equally, you will sit amongst colleagues who will scoff at brilliant ideas, based in research and practice just because they are different.
9: If you find you don't enjoy being with the learners, then don't bother continuing. There is no point in carrying on if you don't like being in the classroom. Find another career. If it is other things which reduce you to tears (and there will probably be tears or rage or frustration at some point) then carry on. A wonderful manager I had very early in my career was kind and honest enough to admit they didn't get through all the things they were supposed to do and let me in on the biggest secret (you just do the important things)
10: Learning support, estates, technical support - these people are your friends. They will help you more than many of the people who are your line managers. Be nice to them (it is surprising to discover not all teachers are). They can make an enormous difference when your printer breaks, you need another whiteboard or one of your learners has an uncontrollable outburst of rage.
11: It's OK not to be top of the class. I've seen teachers burn out simply because it's the first time they've not been 'the best' at something. Similarly, I've seen really bright, well educated people who can't empathise with failure or understand lack of ambition. If you want a job where everything goes well and you get lauded, this isn't it.
12: There will be a lot of talk of 'team' but the truth is, it's a lonely job. You might be lucky to share your classes or course with a great colleague but you might also be ploughing a really lonely furrow. It is surprising how you can find support and succour from teachers of subjects outside your own area. You might teach art but find your teaching philosophy is more compatible with that of a maths colleague. That's fine.
13: Learning the nuances of exam boards is painful and you should apply to go on training as soon as possible. It will help. It won't help with the rage and frustration you will feel about exam boards as time goes on, but it will at least help you understand what you are trying to achieve with exam classes.
14: That PGCE folder full of theory. You will wonder what it is for. At least I did. I still couldn't tell you what a 'learning cycle' is.
15: You will inevitably try to teach people in the way you learn and will be baffled by their failure to achive enlightenment.
16: If you are working harder than your learners, something is not right. You will work harder than your learners. Something is not right. It isn't you. It is the wider system. It is still useful to remember this rule when planning and preparing.
17: If you are unlucky your school will insist your planning and preparation looks exactly like the next person's planning and preparation. This will be painful because you have a totally different brain and working methods. Remember when you wrote that mediocre essay with lots of words just to get it in? This is the planning you do on the school template. However, you do need to plan properly and it is worth spending serious time on meaningful planning that you actually intend to use. I always break down topics, learning objectives etc by the value to the course and the time spent and produce a colour coded document which I never submit to anyone. I'd be lost without it, but it's for me. It's not for OFSTED or for evidence for my managers, it's for me.
18: Don't be afraid not to know. It's OK to tell a learner to look something up or ask them to correct your spelling. They won't mind as long as you are trying your best.
19: Classroom management is simple. Be calm, be polite, have clear tasks and have some strategies for groups. If you are reasonable and treat them with respect, they will reciprocate (99% of the time.) A few consistently applied rules with a rational justification works better than a rule book. You need to be enthusiastic and pleased to see the learners everyday.
20: Praise (when earned) goes a long way. It is especially effective if given 1:1. Equally, don't avoid challenging laziness. My only real rule (beyond not hitting/bullying each other) is that if you try, I'll be nice to you. End of.
21: Don't be a hypocrite. My learners aren't allowed food or hot drinks in the classroom. I don't have them. I don't check my phone whilst teaching. I think that goes a long way.
22: Some of them are cleverer than you. That's ok. Respect that.
23: It does get easier. You build a set of lessons you can take 'off the peg.'
24: The fact I am writing this should tell you a lot about how difficult the job is but also how rewarding it is.
25: The fact their are 25 points also indicates there is no magic answer to 'good teaching' but there are things worth investing time in. AFL can shape and guide you lesson by lesson, week by week. Knowing how the learners feel about the work helps you plan. If they realise you are planning for them they'll appreciate it. They might not buy you flowers but hey, they're forced to be there! What do you expect? Gratitude for shoving the ideology of the state down their throats?