After dropping skydivers in FL100 I put the nose of our C182 down, keep the
speed sligthly over 160 kts. At left base I've slowed down to 100 knots. At
about 300 ft above ground I pull the nose up until the speed sinks to about
90 knots and I lower the flaps all the way down.
Then I land her on the very spot I want her to have, and it takes after
touchdown about 600 ft to take the first turn. Mind you, it's possible to
land at 45 kts, but without any crosswind.
They say a C206 flies even nicer....

Seriously (?), if you notice that your Cessna is sinking to fast with flaps
fully extended, why would you extend them to 40 degrees? 25 degrees would do
and if the speed or altitude is to high or to (s)low, you can do something
about it with. Use your manifold, your right hand should be at the black
handle all the time anyway.
So, at 300/500 ft (I think you'll be flying at that altitude at 0,5 mile
final) and a speed of 70 knots, I would keep the flaps at 25 degrees.
At very short final, keeping your eyes on the speed as well as on the rest,
you can extend the flaps to 40 degrees.

The best way to get the hang of it is to get in your C182 and practice touch
and go's up to the moment that someone will ask you to fly a righthand
circuit instead of a left.
But the most important thing is to enjoy yourself.