I by no means claim to be an expert on this subject, but wanted to document my experiences so that others can learn from them. First I think it is important to give my perspective, I own 10 acres of which more than 9 acres of it was covered in trees and brush. Most places it was hard to even walk through. Over the years I have cleared it to the point that I have maybe 2.5 acres cleared to grass and garden and another 1.5 acres of wooded areas that has much of the under-story gone so I can walk through. So let me explain my approach.
You are going to need a chainsaw. I’m not talking about a $750 saw used by a lumberjack that is cutting high volumes of wood. Go to any of the big box stores and buy a $100 14″ chainsaw, and pick up a couple of extra chains while you are at it. You want something small because when you are cutting brush and small trees you don’t need a big saw, and more importantly it will be lighter. I assume if you are reading my blog this isn’t something you do for a living. You will find this is hard work and after a few hours you will appreciate a small and lighter saw.
When you are cutting to clear an area cut very close to the ground. If you are harvesting wood you generally cut 2′ or more off of the ground, and for larger trees I recommend cutting at a height that is comfortable for you to hold the saw. But when your goal is to clear an area you need the stump as flush with the ground as you can get it. Yes this is hard on your chain as you cannot avoid hitting some grit and dirt, but sharpening a chain and replacing it sooner is much cheaper than the repairs to your mower when you hit it.