Matching the saw to the wood. Even a small saw will do the job, in this case 35cc's in some very soft poplar. Wouldn't even think of trying it on this much rock hard dry ash.
I love small saws. For brush-work and light firewood duty, they can't be beat.
I'm working my way through trying many of them. 42/242, 024, 543, 540i, 346/350/353 (bigger end of small). I also have some 40s sitting around that may turn into a saw someday. Trying to find the perfect match of fit/feel for my hands and frame, power:weight, and longevity. There's been an anniversary edition 36 sitting at the pawn shop for months. Just can't get myself to test it, as I have too many already. Small saws are the bees knees.