As someone has already mentioned earlier in the thread, there are a lot of people on the Stage 1 Selection Days and it is very easy to be lost in the crowd. However, it's better to be lost in the crowd than sticking out like a sore thumb.
If you're serious about ATC as a career though, then it will stand you in good stead to start as you mean to go on through the college and your validation.
For Stage 1 I would definately say, smart trousers and shirt at the very least. I'll be honest, it does irritate me when I see people dressed in jeans/trainers/t-shirts for their initial tests as it gives off the impression they aren't too bothered about the job.
When you're valid and a shop floor controller you can start dressing down and wearing what you want (within reason obviously!) but until then keep it smart.
