It comes with good and bad like anything else.
You have the really good ones who learn the business and get their own vans pretty fast but you're really happy for them and happy you didn't have any issues and you made money even for that short period of time. And you get the ones who know it all and if you dare to say something they quit, or think they know it all and then read here on the forum how they become bankrupt.
Over time you learn to read people a little bit better, you learn to have a good contract and you learn to incentivise the ones who are worth it.
About incentives... I'd say it's about money in the first place (paying a littel bit better than others, paying a little more for longer contract, helping with advances and most definitely paying EVERY week) but also about the way you treat people. Think and act like you're one of the better ones out-there, and the better drivers will get to you. (or at least this is me believing there is a God waching over us)