How to paint furniture without visible brush strokes?

Charlotte: A foam brush may help... or spray paint... just spray many coats on lightly --- to avoid drips.

A foam roller or a paint sprayer have always done the trick for me.

I use a foam brush and foam roller. You can spray paint if you can work outside but you lose a lot of paint that way.

Don't use a brush

Here's my tutorial on painting furniture, I think the key is using a good brush! I recommend a Purdy brush https://www.youtube.com/watch?v=C1Jle1SVD7M&t=2s

Personally I like the texture I get with a foam roller. There are products that you can add to your paint to extend the "open" time. They thin it down enough that the brush strokes will flow away. Or you can use oilbased products that are naturally self leveling, but stinky.