1. Do not be a long-haired cat.
(1a. Actually, do not be the offspring of somebody's fancy pedigree long-haired cat and a smooth-talking tom from the mill down the road.)
2. If you must be a long-haired cat, avoid climbing through hedges backwards, running through leaf-piles, and chasing small squeaking rodents through dark and cobwebby places, all of which will get stuff tangled in your coat.
3. If this is unavoidable, at least limit yourself to 3 hours a day of things which will leave you with large clumps of matted fur.
4. If that proves unavoidable as well, at least don't go on a massive getting-stuff-stuck-in-your-fur spree for several weeks while you're being looked after by neighbours who are afraid of the manic yowling clawing biting rage demon that you suddenly decided to turn into when they tried to brush you.
5. Avoid the vet. Avoid, avoid, avoid. This can be best done by disappearing into an alternate dimension when the cat carrier appears.
6. If your plans are quashed by trickery involving distraction with small pieces of ham, attempt to get yourself banished for life from the vet's by launching yourself at the first person you see in a surgical-looking outfit when you are removed from the carrier, claws flying.
7. If you are foiled in this by a hand holding the scruff of your neck, wail piteously so as to suggest you are being beaten. Last-ditch attempt that probably won't work, but it's got to be worth a try, right?
8. Because otherwise, you will end up looking like this:
9. And nobody wants that.
10. Still, at least your brother still loves you.
Oh dear...
I do hope that said cat doesn't have to suffer this indignity for long!