I have done a fair amount of splitting with mjdeere. He usually starts at the butt and I start limbing/
As others have mentioned, it all depends on the situation, and each tree is different. But my general strategy, where there is tension involved, is to remove all of the limbs that I can first, and get the trunk mostly on the ground before I make my first cut through the trunk. The way I see it, with the limbs out of the way, there's less obstacles to trip over. I'm not worried about the tension in the tops really; if the saw does get pinched, a good yank can free it. But if you get it pinched in the trunk, you're probably gonna need another tool to get it back. And the more tension there is on the trunk, the greater the risk of getting pinched. It just seems safer in general to me to remove the tension in small increments by removing branches, rather than in large increments by starting into the trunk first. This all assumes the trunk is suspended off the ground by the branches. If it's already laying flat on the ground, I'll walk it starting from the butt end, marking my lengths and limbing as I go. Not saying anyone is wrong here, that's just my thought process. After a while you'll develop your own system.
Shawn you explain things so well I think we all are saying same thing really. I like to do it this way but everything depends on the situation your looking at that changes every time, be it tension, rolling, location, etc etc..
As above... fall, drag to landing if needed, limb, mark with mingo, then buck. Always start at the butt so that if there's a wasted partial cut it's at the skinny end. I hate wasting a half round at the butt end where the loss is greater.
Took down a Red Maple yesterday (more than one, actually), and it went down between a couple good sized Poplar, and bent a small Maple over so the top was trapped on the ground. Talk about tension. Reminded me of a catapult. When the kerf starts closing, I pull the saw, then move down a little farther. Usually will cut about 4' down from that cut and try to do it from the underside if I can. That'll release the initial kerf. Lots of little tricks to this tree cutting thing, eh? As was initially mentioned by Dennis, and also by a couple others, every one is at least a little different. I mark and cut as I go, trying to minimize walking (bad knees). I hate to start at the small end and then end up with a few inches of butt end wood that I can't really use. I'd rather waste the small end.
Like to start at top, get the limbs in the air and small stuff out of the way. Then I go to the trunk and buck it, but as said before each tree is different.