Kapton tape is your friend for hot air. It's cheap and you can get by with scissors.
Tape out anything that you're not reworking, use tweezers and push down the edges against the board to seal as best you can, and then flux it and blow.
It'll hold things in place and wick away the heat from anything you're not trying to rework. I went from a near 0% success rate to near 100% with it.
To protect larger areas, you can use aluminium foil. It's usually best to hold the hot air pencil at a right-angle to the board; if you angle it like a soldering iron, the excess heat all goes in one direction and you're much more likely to blow off small adjacent components.
To be fair, it takes a little practice IMO and until you learn how to use flux correctly etc., it can seem very unattainable to ever learn well.
I got a huge confidence boost from one of the old engineers with rubbish eyesight. Thinking “If HE can see well enough to do 0603 and smaller, then so can I!” :D
A few hours practice on scrapped electronics made a big difference for me.
You don't have to 'keep flipping the board over' when doing through hole either. Just stick all of the components in, fold over two legs on chips and passives, then solder all of them in one go.
If you're blowing off stuff, your pressure setting is too high. I usually start at the lowest setting, and only go up if I need to deliver a lot of heat to an area.
So for me, a loupe/microscope and a fine SMD iron is the best option. I have some China-model that uses Hakko tips.