Start Small
Start Without The Chainsaw
No matter which saw you start with I urge everyone to start small. Getting to the goal of, how to cut down a small tree with a chainsaw, is a laudable goal but there is a lot to know before cutting down even a relatively “small” tree. In my experience, the Sawzall is a great tool to practice felling small trees(1″-6″), delimbing, and bucking. I use a pruning blade which makes quick work of processing trees. I think the real benefit of initially using the Sawzall for felling trees is gaining a feel for the physics of a falling tree and seeing how crucial hinge wood is. Starting small also gives you an understanding of how every tree is unique and comes with its own complications. Some of the many complications are covered on the Know Your Tree page.
Some common complications when felling a tree are a tree that is limb locked with another tree or has a potential hazard in its falling radius. You may feel silly making these assessments on a tree only five feet taller than yourself, but if you can build the habits and muscle memory it could help you avoid real dangers in the future. If you have a limb-locked small tree you can witness in a small scale the potential danger of a Widow Maker branch when you scale up.
When you drop your first 13”+ diameter tree it is an intense adrenaline rush. My first tree of that size was close to my house which may have added to the intensity. However, every time I fell a tree it is a pulse-racing event in which I take the cuts slowly and always have an eye on the tree’s canopy when wedging over a tree.