Pre-five children must not be passed between multiple carers on a daily basis, Ronnie Hill, director at the Care Commission, told MSPs.
Services had to be flexible to suit parents and preferably on a single site with fewer adults engaging with children. It was especially important for children up to the age of three to have continuity, Mr Hill said.
Jacquie Roberts, the commission's chief executive, appealed for "investment in status, quality and resources - and the independent and voluntary sector is part of that".
Ms Roberts said: "Services in general are really quite good and we are looking for improvements. We should be proud of the standards we have."
However, health, care and education should provide an "all in one" service in the pre-school sector and not just for families in difficult circumstances. All families faced problems looking after young children.
Part-time nursery education for three and four-year-olds suited some parents but many needed extended care, such as that provided by childminders who continued to be poorly paid. School premises were not as available as they should be, Ms Roberts said.
She appealed for better training for around 6,000 childminders who filled in gaps in provision