Best way to paint misty look in Acrylics?

Water down the acrylics and use a cloth or natural sponge to press the paint on, I have seen people apply with a brush and then wipe at it with a sponge/cloth but that never worked for me it would just look smudgy haha.

I prefer a sponge to a cloth personally I feel that it gives a nice light texture that cloth doesn't give but to each their own :)

Good luck

I don't use acrylics myself but only oils and I think the same technique would apply. I have done a whole series of fog paintings and I did them without a brush. I get that misty look by wrapping a cloth around my finger and using that as an applicator instead of a brush. Works for me.

Use light colors (I'm guess you already knew that) and use a lot of water to make the paint semi translucent. Apply with cloth or tooth brush (dab it) .