Being English, this video is directed at apples, pears and stone fruit, but the same tips can be applied to any fruit tree. Like it says in the video, pruning isn’t difficult, the key is to do small amounts, often.
I tend to time our main pruning session (of citrus) to just after harvest, which is usually autumn/early winter, but in subtropical Queensland it doesn’t really matter that much as long as its done before the new flush of growth happens in August/September. Frequency-wise, I only give the citrus a ‘hard prune’ (think Peter Cundall) every 2 or 3 years with ‘maintenance pruning’ (removing weak or diseased growth, crossing branches and thinning out congestion) whenever its needed, in between. And because our Aussie soil is generally a lot shallower and impoverished than English soils, I always give the tree a good drink, with at least one watering can of seasol, afterwards, to help reduce the shock and spur on new growth.
I also apply the same never-remove-more-than-a-third rule when harvesting kale, silverbeet, spinach and cut-and-come-again lettuce, so you don’t tire them and they can continue to grow healthy leaves for you :)