You finally have your paint looking how you want it to - it's clean, scratch-free, protected, or just brand new. But what now? It will certainly not look this good in a year or two, right? Wrong. It is certainly possible to keep your paint looking as clean as you desire for as long as you want.
Most scratches tend to occur in the wash & drying process, and so taking proper care here can have a massive impact on the look of your car. While the wash itself varies person to person based on products used/time available, there are two main factors which are important to keep in mind: dirt/grime is sufficiently removed from the paint before any rags/towels/wash mitts/sponges contact the paint, and lubrication is always present.
Rinsing the car very thoroughly should be enough to disperse enough dirt to allow the soap/chemical step to begin. The higher the flow-rate of the power washer being used (not necessarily more pressure) the quicker this process should be. When it comes to drying, the paint should never be on the verge of drying out. If it is, then the safest step would be to use a drying aid such as an instant detailer spray, spray wax, or sealant to add lubrication (ideally, a lubricant such as these should be used anyway to ensure there is no dry contact between towel and paint) or simply wash & dry single panels at a time.
These steps above apply to wheels too! Care for your cars new shoes will keep them looking mint as long as you desire. While more tricky because of baked-in brake dust over time (especially in the wheel barrels), regular washing will ensure nothing becomes permanent. Finishing them off with a clean towel and application of the same wax/sealant/instant detailer will both keep them cleaner longer, add gloss, and ensure they receive minimal scratching in the drying process.
The biggest commitment here is time. Running your vehicle through touch and touch-less car washes certainly provides a massive time benefit, but both will have your car looking dull very quickly. Touch washes will (obviously) pass the same brushes over your car which have gone over every other car that day, rubbing along any dirt and rocks it picks up (great if you like textured paint!). Touch-less, as safe as it sounds, needs to make up for this lack of contact by using very strong chemicals which are known to stain rubber, plastic, and chrome trims. Simply put, nothing will be safer for your car than a care-driven hand wash.