If there is any peeling — and there usually is somewhere — it's essential to scrape off any loose paint. This doesn't just mean the parts that are already separated from the wood and ready to fall off on their own. Each spot where paint has peeled loose needs to be scraped thoroughly until you can no longer get the sharp corner of a putty knife under any of the surrounding edges of paint. Then, the bare spot needs to be sanded until the paint edges are smooth.
The other difficult part is getting a painting contractor to show up. While this generalization does not apply to every painter, you can rarely get a paint contractor to show up to look at the house and to later produce a written estimate. It's hardly the fault of the painting contractors; it is a combination of the contractors being smaller operations along with a high demand for their work. House Painting