i disagree with the last comment,
im not saying you have to do full braking and downshift (making your rotors red hot)when driving normally, but just braking and downshifting(+rev matching) to go around a corner is way better than shifting after you make the turn since you can accelerate in the proper gear OUT of the turn.
its 2nd nature to me now, i downshift every single time i have to slow down so just incase i have to accelerate again suddenly im already in the correct gear to do so.
basically you...
are going whatever speed, you brake,
rpms drop to around 2000-2500
brake, clutch, bilp throttle + downshift 1 gear, unclutch
brake, rpms drop again to 2000-2500
brake, clutch, bilp throttle + downshift 1 gear, unclutch
now you are at around 2500-3000 RPMs, and you can accelerate out of the corner
also comming up to a red light thats about to turn green, you are already in the correct gear to accelerate so instead of the light changing and you are 5th gear with no power, you are already in 2nd gear ready to accelerate again.