The single most common gardening mistake TPP observes is poor pruning, including none pruning. Knowing how plants grow is essential, but you can learn most of what you need to know by careful observation. Knowing what you want to accomplish is also essential. Knowing that poodling (and here) is a total no-no is totally essential. So what can possibly go wrong? No wonder many people fear pruning to the point that they make an even greater mistake - they don't prune at all. Now you put pruning shears into TPP's hands and that mild-mannered, easy-going botanist turns into a clipping demon! Don't stand too close, and please, never, ever point! Snip! Oops. Sorry. Of course some plants are a struggle. Two dwarf apples of the same variety, and one is well-behaved and the other is growing all over the place. They are clones aren't they? And who would have ever thought that one of the most difficult pruning challenges is a thread-leafed (branched) Chamaecyparis? Don't prune enough and it takes over; prune too much and it won't grow back. Oh, and it grows fast too, so it's real battle. Here's the things to look for with fruit trees: multiple leaders (leave only 1), downward growing branches, criss-crossing branches, weak branches, damaged or broken branches, suckers (a problem with grafted stock), vigorous new growth (reduce by 1/2 to 1/3). If more than 2/3s of a branch needs to be removed, remove the whole thing. Cut branches perpendicularly and cleanly. Cut branches off flush to the stem; they heal faster. Don't cheap out on your equipment. Don't ever go near a tree or shrub with a chain saw unless to intend to basal prune it. One real problem is that you need the right size clippers for the job, and they get bigger for bigger branches, but then they can be too big for some people's hands (this from Mrs. Phactor). Good loppers are needed for big branches or major pruning, and they can provide a lot of mechanical advantage. Keep them sharp. If you find a rusty pair laying around somewhere, it may belong to yours truly. A pair went missing somewhere out there a few years back. TPP's earliest lesson on pruning came from a great gardener who told his young helper to prune out the oldest stems from some lilacs and beauty bushes. When TPP asked how much to prune, his response was "there should be room for the birds to fly". When the job was done, and being inspected, he let out a big sigh, "Ah, here I was thinking of sparrows, and you were thinking of eagles." But, nonetheless, for the next few years they looked great.