This is going to be a good thread I think.
Many pros and cons. A lot of it depends on
-the rifle (how heavy? How long? How much recoil?),
-the terrain (where you hunt), and
-style of hunting (still? Mobile? Means of transportation?)
Fundamentally, a good field position is as low as possible, utilizing a front and rear support. Mass is your friend.
In the field, however, prone position can limit line of sight. Carrying unnecessary weight can result in fatigue, and elevated blood pressure.
Personally I use my pack for a low rest when possible and lightweight shooting sticks when I need to get above vegetation.
I like to walk and sneek and feel generally unencumbered by tools/gear. As such, sacrificing a bit of shootability to gain hunting ability is an easy tradeoff.
That said, there's a reason bipods are so popular. They're a good rest, but they are also a good stand, offering a safe means of putting the rifle down while keeping the muzzle, action and optics out of the dirt!
Best practice is simply being consistent with whatever method you choose!