More than 75 would-be handymen had to call ambulances during the first half of the year, the NSW Ambulance Service says.

The DIY injuries included 17 separate incidents in which people either partially or completely severed a toe or finger using lawnmowers, mulchers or hedge trimmers.

It's moved NSW Ambulance Inspector John Brotherhood to remind NSW residents that some things are better left to the experts.

"People get on the roof and tie themselves to the TV antennae but it's not strong enough so they fall off," he said in a statement on Saturday.

"Or they're inside nailing things to the wall and they don't know where the electricity is and they electrocute themselves."

Some incidents were especially wince-inducing - like the man who was trying to drill holes in a metal sheet that was resting in his lap, but instead drilled through his testicles.

With spring around the corner, Insp Brotherhood said gardeners needed to remember never to place their fingers or toes under a lawnmower while it was in operation.

"We had a guy who decided to trim his hedges so he thought a good idea would be to pick up his lawnmower and run it across the top of his hedges and it took the ends of his fingers off on both sides when he put them under the lawnmower," he recalled.

"Ninety minutes later, we had exactly the same job about four kilometres away.

"The patient said he had been travelling home and saw this earlier bloke trimming the hedges with the lawnmower and thought, `That's a good idea!'"

The ambulance service's tips for surviving a home reno include checking with experts first, carrying out jobs in company, and following the instructions that come with a tool or product.