I did it nearly 3 years ago (year 6 - year 1/2). Throw out all your expectations and imagine you are an NQT again. None of my standard time filler activities (apart from heads down thumbs up) or lessons I could pull out of the hat and re-use when I was up against it were any good at all.
On the plus side, the progress they make is absolutely incredible. They don't get sarcasm but are enthusiastic about everything. You are teaching them things for the first time - I remember the lunchtime a group of girls came in clutching handfuls of grass from the field which they had pulled up and found roots at the end of, just like I'd taught them - they'd brought it in to show me!
Expect everything to take twice as long, if not longer. Take nothing for granted - you will need to teach them to start to write on the left hand side of the page and then go all the way across to the middle before coming down a line and starting on the left again. Don't expect them to do their work in their own books, nor will they start to work on the next empty page - many children will pick an empty page at random to write on. That's why they all leave their books open in the middle of the table as it saves me all the hunting through to find where they've put their work.
There are lots of differing ideas about how much child initiated/adult led learning should take place in the day. Best practice suggests the children should have access to continuous provision throughout the day and then the teacher/TA work with focus groups. I can't do it - it does my head in! I can't cope with the noise and chaos of some children doing their own thing while I try and get some to concentrate on what I'm teaching them. Best practice also says that there should be no difference between the end of Reception and the start of year 1 - transition should be planned between the two so it's as seamless as possible for the children.
I've had my new class every morning this week as we do a transition week not day/hour. I've compromised between my comfort zone of "traditionally" structured lessons with whole class input then independent activity and the need for 4 and 5 year olds to be engaged in practical hands-on learning. I've been lucky enough to have 4 adults so I've put them into 4 groups with 4 adults which they've spent half an hour each on over the morning. So my lunchtime they've done Maths, Writing, Art and Free Play (outside!), all in groups of no bigger than 8. It's worked really well for me and I'd like to do something similar for the first couple of weeks in September, if I can get sufficient adults. For those 2 weeks the afternoons will be all child initiated (ie play) so my TA and I can work with individuals/groups. Then after that I'll start to build up the length of my input and move them across to all doing the same subject at the same time in the mornings. As I said, lots of people would say this isn't good practice, but I hope to have them on a "proper" timetable by October half term.
Finally, there are some great facebook groups I've recently joined. Reception/Year 1/Early Years Teachers is very active, as is the Twinkl KS1 group. KS2 teachers - specifically year 1 is also very very useful. I skim over the posts there as they tend to make me feel inferior. I have to tell myself that nobody posts their bad ideas, so it's not surprising that everyone on there seems to be amazing practitioners. But there's a wealth of experience and loads of good ideas.
Wow - mammoth post. Is that the sort of thing you were looking for?!?