The 30% woven polypropylene is smooth and doesn't hang up. It's also very tough and long lasting but probably more expensive than most folks could handle.

The most economical way to net is a rectangular block of closely spaced trees and net the entire area. If the cheapo netting is done this way and supported up off the plants that would be the best cheap system I've seen, see below.

Here is a link that might be useful: bird netting support system

Where do you obtain the heavier netting? I would be using it more over berries and grapes than on fruit trees.

It's sold at dozens of places. Do a google search on woven black polypropylene shade cloth. One supplier below.

If just to keep the birds out I'd go 30%. If you need some shade, berries would do well under 47%. Be aware this is a lot heavier than normal bird netting and might damage your plants without support.

Here is a link that might be useful: shade cloth