Why spank at all? If there's a problem in the relationship why not discuss the problem and work it out without spanking?
In my spanking relationships discussing the problem is a given. Spanking relationships are really no different than Vanilla ones. The main difference is that two adults have sat down and decided that the best way to resolve certain conflicts within the relationship is through spanking.
This does at least two things. One it causes the Spanker to be more responsible than the spankee. You can't justify spanking someone for bad behavior if you the Spanker are guilty of the same behavior. The Spanker should always be looking at their actions and set the example. The second thing it does is make the spankee accountable. Generally the spankee is the one who is constantly battling something like tardiness, pickup after themselves, keeping appointments, etc. It doesn't make the spankee a terrible person but they and their Spankee realize that the best way to keep them on track is through spanking their naughty bottoms.
It's really a respect thing too. I don't respect a woman who wouldn't willingly get across my lap for a spanking when she needs it. And most women who get spanked wouldn't get across the lap for a spanking if they didn't respect their Spanker. In other words, "He's not a real man if he doesn't spank me." Trust me I've heard that many, many times.