It is true he licenses his name for branding purposes but actual deals he was involved in worked out great. You can read the Art of the Deal for specifics but one example from the top of my head is the Wollman Rink in Central Park.

Having fallen into utter disrepair during the New York City fiscal crisis, unable to make ice, the city’s Parks Department embarked on a total refurbishment of the facility in 1980, estimating it would take two years to complete. After six years and having flushed $13 million down the drain, the city announced they would have to start all over again and it would another two years to complete.

Then Trump convinced the mayor to let him finish the job.

Instead of failing, Trump finished the job in just four months at a final cost 25% below the budget. It wasn’t rocket science according Trump. It was common sense and “management.”

There's also other examples, such as when the UN was constructing/renovating a new headquarters in NYC and Trump testified to congress telling them how they could save money on the project, because he had himself just built a skyscraper (tallest residential building at the time) right across from the site for a cost of $325 million. He told the senate committee that their budget was $1.2 billion, and that it would end up costing them $3 billion because they don't know what they're doing. He said if it was done right it should cost $700 million. He was right, they didn't take his advise, they spent close to $3 billion, 10x more than what he spent on a much bigger and better building just a few years prior.

There's numerous examples of this, the argument that Trump doesn't know what he's doing as a businessman is a weak line of attack.