I had duckweed a few years ago. It all turned brown after the first fall frost. I used a pool hand skimmer (screen on a stick)to get it out.

Netting it out is one way or you can try carefully skim sucking it out with a wet/dry vac.
You don't say how big your pond is or what climate zone you are in.
The size of your pond and the climate of your area, will contribute to the control or demise in winter of the duckweed.
It sinks down in winter and reappears in the spring in some folks ponds. In mine, the winter kills it off completely.
Duckweed can be a b---er to get rid of. During the spring and summer my fish eat it and keep it under control, so I never have an over abundance of it in the pond.
"Horton"

I wish you could send it to me. I love Duckweed and can't keep it - my 4 goldfish eat it like candy. I bought some at a local nursery and it's all gone - your fish don't eat it?

'Best way' might vary from the circumstances of one pond to another.

On a dinky rockery pool, a harsh mist spray can blast duckweed over to one side where it is easier to net floating plants out.

On a larger natural pond, topping the pond up prior to heavy rain storms stands a chance of flushing the bulk of it out of an outflow

On a pond with fish, stopping feeding the fish might persuade them to turn on tasty floating plants

On a pond that has been devastated by invasive plants, emptying the pond, leaving it to bake in the sun can do a thorough job where neglected plants have become rampant

'Nuking' a pond of legacy problems can be a convenient time to remove surplus plants, debris, to reconsider choosing more appropriate aquatic plants