transparency. A good sharing attitude and work ethic. If you want bands to sell tickets for you, be open minded and transparent towards sharing why you need them to sell tickets and this amount in order to cover overheads, rental costs and so on. This way at least bands know that they are working their ass off for something thats honest and in the light rather than for someone who just has every plain intention to rip off their money.
a good organiser should also be well, like the namesake, well-organised, preferable able to communicate well and be prepared in the case of emergencies. Not to mention taking the extra mile and building rapport with the bands. If you are nice, people will be nice to you(at least for most)like the saying goes, ,"do unto others what you would want others to do unto you".