The simplest way to think about it: a regular clean maintains, and a deep clean restores. Regular visits take care of what builds up every week, like countertops, bathrooms, dusting, vacuuming, and floors. A deep clean reaches everything that builds up slowly, such as baseboards, door frames, cabinet fronts, ceiling fans, and the soap scum on shower glass.
If your home hasn't been professionally cleaned in a while, start with a deep clean. Trying to maintain a house that hasn't been reset means every regular visit is spent catching up, and the detail work never gets done.
After that, most households do well with a regular clean every week or two and a deep clean once or twice a year. In Dallas-Fort Worth, a lot of families like to schedule the deep clean before the holidays and again in spring.
Homes with pets, young kids, or allergy sufferers usually benefit from more frequent visits. Dust and hair build up quickly, and keeping up with them weekly is far easier than tackling them monthly.