OP - re yr question & please bear in mind they may have changed it /relaxed "rules"- I went the year Sophie Ellis Bextor danced with Brendan in semis.
I live several hours away & don't know Elstree & was going by public transport. In small print on the email tucked away it said something along the lines of this doesn't guarantee you entry & to be there before 3pm.
About 10 days beforehand I rang Elstree studios to ask a couple of questions in prep for my visit - I spoke to a very helpful lady who worked on film marketing and was nothing to do with SCD who actually laughed when I said something like - I know it says be here by 3pm but I am going to get there a bit earlier..... after she stopped laughing she said to me if you get here by 3pm you wont get in. She said they start queuing normally from 7am & there were she understood less than 400 tickets as lots of celebs & family members/past contestants fill seats.
Me & my friend went as early as we could get there because we would rather stand for hours & get in than have missed the chance to get in.
As I said earlier I think we were there about 8am (?). Luckily whilst freezing cold (it was mid Dec) it didn't rain. My friend walked to front of queue & counted back - I think we were in the 80's in queue. At about 9.30 a staff member came along queue saying they would start handing out your numbers at 12 Noon. Whilst one of us stayed in queue the other walked over to Tescos to get takeaway coffees.
There was a lovely lady ahead of us in queue who had been before (!) - she told everyone to stay in the queue because the give you a ticket per person for your seat - you couldn't collect for someone else.
At around 12.30ish we were given our tickets - no 81 & 82. We then left and went to Elstree High Street found a restaurant & had a very long leisurely lunch - we also used their toilets to apply make up/ strip off layers & glam up in general before walking back for the 4pm deadline we were given to return by.
Whilst in the restaurant we met 2 young women who had got the last 2 tickets handed out ! they said there were a lot of people behind them who were turned away. We also sadly met 2 elderly ladies lunching who had misunderstood their email & thought they just needed to get there by 3pm to be ushered into studio & hadn't queued - they ate up speedily & went to studio to see if they could get in - no idea what happened to them.
When we went back b y 4pm we were in a holding area with refreshments . When you get called through they do it by number & the lower your number the better your seat apparently. We ended up sitting opposite the judges near the stairs on the right hand side as you look at it on TV - we were about 4 rows back - had a great view & thoroughly enjoyed it all. Getting out at the end after they also film the results show wasn't that bad - they were very efficient - even the queue to retriebe mobiles was speedy. It was AMAZING & we still talk about it & how luck we were to get tickets. I apply every year along with 5 million others !
Sorry that was long but I definitely would get there earlier - you would hatye to miss out .