"What is going to go where?"
That is the question I ask myself before bucking any limbs.
And sometimes I need to stare at the down tree for a bit to figure out the "order" in which I am going to cut the limbs off...
If I cut that limb, what is going to happen? Etc.
This can be quite complex. You have a down tree with a bunch of limbs up in the air, if you cut one side, it will alter the "balance" and it will roll. Or same with the other side.
Or with limbs on the ground supporting the tree or keeping the tree from rolling... If you cut these, the log may fall on your toes or the log may roll.
Then there is the "spring pole" which is a limb being bent way back. If you cut it, it could fly forward and smack you in the nose!
I guess the key words are "potential energy". Is there potential energy stored up? How can you safely release that potential energy?
I think because trees are all so different, there would not be any one set of rules which would cover all situations. I guess experience is the best thing!
For me though...
For limbs up in the air, I like to cut these first. Get rid of that potential energy. And I like to alternate sides. Cut one on this side, then one on the other side to keep the "balance of weight" the same on both sides. Maybe cut three smaller limbs on one side, then one large limb on the other side.
THEN I cut the limbs under the tree. Some of these are under great pressure as they are supporting the entire log on one side. For these and "spring poles", rather than making one cut and having everything suddenly go flying uncontrolled, I make a series of shallow cuts to slowly dissipate the energy.
Like the guy in this picture is doing...
The limb slowly releases its energy.
Another trick, if the wood is for firewood, is to use an "open face cut". With this the "hinge wood" will keep the base of the tree attached to the stump. Leave that until last and it will keep the tree from rolling while you are bucking the limbs.
Here is an open face cut...
Also if the tree remains attached to the stump, it will be up in the air as you work your way to the stump cutting. This will help to keep the chainsaw from touching the ground as you buck the log - speeds things up a bit.