I pack a little bit, just to hold in more water. I use promix and it is very light and airy, but it all deppends on how well your soil holds water. so be carefull.
Yeah, what I've been doing after we water them is lightly pack the soil surrounding the edge of the pot and then add a little more soil medium over the top and misting it lightly .
use your hands and pack the dirt until it feels like it is halfway stable to the touch. Especially around the base of the plant. Then water.
It doesnt need to be compacted, just snug.