Just like with any relationship, there comes a certain social ettiquite that allows friendships to thrive, such as being a good listener, kindness, generosity, keeping in touch with people you care about etc. If a friendship fails to have a level of respect and consideration then it just won't work out.
Most people understand these unspoken rules of friendship, but if you've never worked with a graphic designer before (or even if you have) then it's good to know what designers find important so you can be the best client ever and give your project the best chance of success.
So I’ll let you in on a little secret that will get the most out of your graphic designer and keep everyone happy...