As much as I hate to say it, art and design clients procrastinate just like artists. Of course this doesn't apply to every client you meet with, but I say this to prompt artists considering freelancing or selling commissioned work to clients. First, it's good to know that there are different kinds of procrastination.
The initial procrastination is called design procrastination. This is when your client knows the name of what they want; a logo, painting, banner, etc. but the client can't translate words into pictures as easily. This is what can make the initial designing stage frustrating for both sides but this is natural! This is when both sides are trying to understand what the other side is envisioning. We sketch, choose colors, and look at similar styles to try to pinpoint what will make both sides happy.
REMEMBER! No one is entering this business relationship to hurt the other person. No one is hoping to cheat you or slander you. Some love to get work for a lower price but that has nothing to do with you as an artist. Let Hobby Lobby handle the 60% off deals because that is unrealistic for the amount of work and material expended to make personal commissions. Not even Amazon has a fast delivery time without a high price on shipping. Which clearly leads us into the dreaded payment procrastination.
This one can be a bit tricky and if you are an empathetic business owner, you understand that business is nothing more than person to person interaction. This means always looking for the win:win. AKA the client is just as happy as you. If you charge higher rates, it is less likely to receive a full payment all at once. I used to hear, "If people could pay for their groceries all at once, they can do that for this work." Not everyone buys furniture, cars, or houses in a single payment. So realize both, that we are already used to multiple payments for a single purchase and it is more helpful for building long lasting relationships.
The last procrastination which is excruciating pain for the creative, is waiting for the 'okay' from the client, clients team, husband and kids. Disclaimer: Please don't think I am whining or complaining here, just giving a perspective on my creative energy in this process. After sending the final design via email, you expect in 30 minutes, I will have the go ahead to start. So just as this idea has fallen into place, I must sit and wait in the anticipation. When engulfed by those creative flows, it is easy to forget your client has their own life! They may be in meetings, taking their kids to soccer practice, or something better than answering your email right now. AND THAT'S FINE. After about 3 hours of waiting, I realize their is nothing to wait on and this final procrastination subsides.