For some people have a detail done is a regular occurrence, but for most it's a special event. Once your vehicle has been detailed, it's essentially to keep up with regular wash and waxes to maintain the condition. Frequent washing also limits bonded surface contaminants that require more effort to remove. Below is some general guidance for washing and waxing.

Always use the two bucket method for washing. Using grit guards further reduces the risk of wash induced swirls.
Dry your car with the sheeting method or a dedicated leaf blower. Your neighbors may think you're crazy, but your car will look way better than theirs.
After major drying apply a spray wax while removing the last few drops of water to add lubrication and achieve that 'just detailed look'.
Decontaminate your vehicle on a regular basis with detailing clay or a clay alternative.
Look for a pure wax or sealant rather than a cleaner wax. They tend to last longer and are easier to apply and remove. Use the cleaner wax to deep clean and protect the paint in one step on a less frequent basis.