The scenario of blundering into a tight valley or other confined location in VMC (implying that you you had awareness of your proximity to the ground the whole time) is different from CFIT. CFIT suggests that you are flying in "cruise" flight, and for whatever reason, the ground suddenly surprises you (you didn't see it coming).
If you want to prevent a CFIT, either fly in sight of the ground, or fly IFR above minimum altitudes.
If you've blundered into a tight valley or similar, you did not think about you entered. If you're doing that at cruise speed, even dumber. If you are flying in terrain, and sudden or aggressive maneuvering may be required, fly more slowly, so you're slower than Va, and flap speed. This will increase your options for maneuvering. But hard maneuvering also greatly increases your risk of a stall spin, particularly if you pull G to do it.
I have trained many pilots to fly a canyon turn, usually on floats. Different aircraft fly canyon turns differently, so there is no one size fits all maneuver for this situation. But a key element is to avoid very sudden maneuvering, keeping things smooth, though unusual attitudes may be flown.
I don't deny that pilots get themselves caught in "terrain", and are unable to prevent crashing into it, but if they saw it, and maneuvered to avoid, it was not a CFIT.