Best thing we ever did. Last September we allocated 10 places and advertised on the local Godalming Facebook group. We advertised a recruit trial night and the 10 places were taken in 3 days. All 10 turned up with parents and we did our show, after 30 minutes the new recruits went off and did some fun stuff whilst we spoke to the parents about expectations and money etc. All 10 recruits stayed as a group and got enrolled, we did't lose any and they are still with us. In Jan this year we ran another trial night but increased to 15 places. Again the places went within days of advertising and this batch are due to be enrolled on the 20th April.
We have decided that 15 is too many in one go so will reduce to 10 again. We have the standard size single hut and the classrooms are too small to handle 15, also the group take longer to gel so for us 10 is a good number.
We have 7 already signed up for a late August trial night but will get 10 who will start in September.
I would recommend this approach, it really works and you can plan your training programme much better. We get people to signup via our website, this makes it easy however, if you don't have that capability just use something like http://eventbrite.co.uk as it's free for no charge events and works well.