Image copyright Getty Images Image caption Everything flows from a good head, says former Ofsted boss Sir Michael Wilshaw

It's that time of the year when secondary schools freshen up their display boards, pick out their best-behaved kids and prepare for open evenings.

But how can parents get beyond the glossy prospectuses and slick presentations and decide whether this is the school for their child?

1. Quiz those hand-picked pupils who show you around

As Geoff Barton, general secretary of the Association of School and College Leaders, admits, schools will always wheel out their star pupils for the open evening: "They'll choose the pupils who are their ambassadors."

And who can blame them? It would be rather worrying if a school gave the responsibility of showing prospective parents around to the naughty, often-caught-having-a-smoke-behind-the-bike-sheds boys and girls.

But former head of England's school watchdog Ofsted, Sir Michael Wilshaw, says asking these carefully selected pupils lots of questions can be very revealing.

"Most of the hand-picked students will say nice things about the schools," says Sir Michael. "But ask them about achievement, ask them if they've made progress from year to year.

"Particularly if they are lower-school children, in Year 7, 8 or 9, ask them whether they've made sufficient progress since primary school, because all the data shows that when youngsters transfer from primary to secondary, their performance often dips.

"Ask if they are taught in mixed-ability classes - in all subjects, in some? Are there setting arrangements in the core subjects?"

2. Ask to go to the toilet

It's inevitable that schools will want to show you around the newly refurbished library or the new sixth-form block. They'll be all shiny and new - how could you not be impressed?

"Schools are bound to spotlight their smartest classrooms and best facilities," says Geoff Barton. "But this is no different from what we do when we show would-be vendors around our houses.

"But you can get beyond this by asking to have a tour, and asking to see, say, the toilets that pupils use.

"Toilets, in my experience, tell you a lot about a school's values."

3. Bring your child to the open evening/day

Michelle Doyle Wildman, acting chief executive officer of the parent group Parentkind, says that while parents would do well to look at Ofsted reports and read up on a school's exam results, open days and evenings are not to be missed.

"There's no substitute for going to the school yourself - the opportunity to visit the school is invaluable."

Michelle says it's important not to leave your child at home: "Go along with your child and gauge their reaction on whether this is an environment in which they'll thrive. Fundamentally it's about finding the right match for your child."

Image copyright Getty Images Image caption Would my child fit in here?

She suggests letting the visit "sink in" before having a conversation about how they felt, as this "gives them a chance to digest it".

4. Listen to the head teacher's speech

Sir Michael says sizing up the head teacher is crucial - and he should know, as he was one for many years before going to head up Ofsted.

"Parents need to listen to the head - leadership is everything in a school. If you've got a good head, everything flows from good leadership.

"So listen to the head teacher and make sure he or she is talking about progress and outcomes and is the sort of person and personality that will drive the school forward."

Michelle Doyle Wildman adds: "The head's speech gives you a good feel for the school.

"Is the school taking a whole-child approach or is it more focused on the academic achievement? That's a nuance you want to get in this process of looking at schools."

5. And then ask tough questions

If the head then takes questions, Sir Michael says parents should not be backwards in coming forwards.

"Try and get the head to talk about what they're doing to improve attainment and improve progress.

"What strategies have they got to ensure that children learn and achieve well? What are their intervention strategies?

"What are they doing with those youngsters who are underachieving? Ask the head to be very specific about that.

"Also, destination data - where are the children going at the end of their secondary school career?"

6. Take a good look at the teachers

Good leadership might be key, but it's teachers who'll have the most day-to-day impact on your child.

Geoff Barton says: "Staff should look like a corporate body, welcoming and keen to talk about the school."

Sir Michael says parents should ask themselves: "What do the staff look like on the open evening? Do they look professional? Do they look like teachers? Are they well turned out?"

Image copyright Getty Images Image caption Do the teachers look professional?

Parents could legitimately ask about recruitment and retention, he adds.

"How many unfilled vacancies have you got? How many vacancies are covered by temporary staff and supply teachers?"

7. Visit the school again - at home-time

Having attended what is an inevitably well-rehearsed open evening or day, Sir Michael recommends doing a bit of Sherlock work and going back when the pupils are leaving to go home.

"I think you can get a sense of a good school as you see the children coming out of the school," he says.

"Parents need to look at the behaviour, whether the uniform is still worn properly, whether they're congregating outside fast-food outlets misbehaving.

"Are there staff outside the school to make sure youngsters behave themselves and act as good ambassadors for the school?

"That's really important because that tells you a lot, I think, about the culture of the school."

8. Write the deadline date on your calendar

Open evenings and days aside, the most important thing is to put in your application forms - and any other supplementary forms that need to be submitted - on time.

Michelle Doyle Wildman says: "You can reduce your stress considerably if you put the closing date on your calendar."

And the deadline dates for places in September 2019 are: