Which software do you use? I am using publisher at the moment.
Best software is an Illustrator, InDesign or Photoshop and even better to have all of them to hand. I mainly use InDesign as it allows to create brochures books leaflets postcards and you can save them as pdf or a picture format. However it cost few bob unless you have other sourses to obtain the software from and it then requires training but can learn on internet the basics and that will be enough to create a good leaflet.
As regards to thickness of the leaflets, to us it made big difference, first ever leaflets we sent out was thick like a post card only a6 one side full colour, and brought in about 3-5 per 1000 and last once which was cheap and thin hardly brought in 1 per 1000, could well depend on the area distributed to time of year etc, but all i know is we have 15000 left and i dont think they will be going out anywhere other than bin as they waste of time and money. I will never ever buy cheap water thin leaflets again.
dash t