Depends on your stand on how you want to thin it. Out here after managing an 85 acre mixed tree stand for 4 years, I am in favor of clear cutting. More wood that way, better for the forest, and better for the environment . Yah, I know the environmentalists do not think so, but no other way of growing trees puts more boimass in the forest. No other way gets you the best trees either. Now that does not include old growth stands that you want to preserve, or younger stands that you want to leave in trees over time and not clear-cut. If I had 100 acers of trees, I would plant mixed stands of trees, and clear cut them in rotation of 10 acre parcels.
The main problem with just harvesting the biggest and best trees is that after a few thinnings, you will have smaller and crappier trees. You need to leave some of the largest trees that nature would favor, and cull the mid-size trees around them. This is so that they are the ones more likely to reproduce and produce seeds for future generations of trees. Which is what you want. In some cases you might want to cut the largest trees if they are near death, or they are diseased or there is a nearby one that is in a lot better shape. It takes an eye and experience to thin a stand for the stand's sake. For the logger and the mill, they will want to high grade or select cut and just take the best and leave the trash for you to deal with in the stand. Again, that leads to a poor stand.
In my experiece, when thinning a connifer stand for longer term clear cutting at some future point in time, you want to thin to leave the best trees, and thin to make room for them to grow at an optimal rate. If you do not do this, you will likely wind up with what is called a stagnant stand. The trees will basically stop growing at a certain point. One or two thinnings are required in a clear-cut and replant 40-60 year cycle.
I have also thinned old growth oak mix stands. In that case we set aside 5 acres in our forest plan, and had the state forester change our forest plan to reflect that. A forest plan is required in Oregon for property tax-deferrals on parcels, and depending on the county, they can be as small as 2 acres. At any rate, in that old oak stand, the fir trees were growing over the canopy and choking out the oaks, which were about 100 feet high. Those oaks were over 400 years old, and presumably they were that age becasue the Indians in that area had burned the area for hundreds of years to create an edge-effect for hunting grounds. Withouth the fires, the connifers grow and crowd out the oaks, maples, madrones, and other lower groing trees. So we went through and removed all the dead snag oaks in there first. We used that for firewood. We then went through and cut out all the grand and doug firs and hauled them out with the ATV or tractor. We cut the tops and branches off and burned them in slash piles, and used the rest as firewood. What was left were a mix of mainly California black oaks, some Oregon white oaks mixed in, and a few madrones and bigleaf maples. That area is now also fire-proof as a result of our removing the firs. If a fire had gone through there with the firs being anywhere from 20-120 feet high, they would have gone up like torches and burned the oak canopy as well. Now is a fire goes through there, there is just grass and bruch on the lower story, and the oaks will not burn in a wildfire.
Well, enough for now... I subscribe to the George Fenn method of planting and harvesting trees. Do a google seach on him and he is all over the place. I met him and his wife, and did a tour of his 400 some odd acres of trees in Elkton, OR a few years ago. He gets faster growth, shorter harvest cycles, and better quality lumber from planting a mix of connifer species, fertilizing, thinning, and smaller parcel clear cut logging. He is an amazing guy, really. Controversial as all get out. But I think he is right about how to grow trees for commercial use.
