''Advise'':-:- “What is a sin?” Whereupon the Messnger said: “When something pricks your conscience, give it up.” (Tirmidhi)

A big part of learning from mistakes is learning to trust our
instincts, because when we make the big mistakes there's almost always
a little voice inside saying, "This is not a good idea." But our nafs
(our lower self, our desires) causes us to ignore that voice. So we
need to learn to trust that inner voice of truth and fitrah.
A person asked Allah's Messenger (sws): "What is faith?" He said:
"When a good deed becomes a source of pleasure for you and an evil
deed becomes a source of disgust for you, then you are a believer." He
again said to Allah's Messenger (sws): "What is a sin?" Whereupon the
Messnger said: "When something pricks your conscience, give it up."
(Tirmidhi)
So the conscience is an effective guide, of course not neglecting
salat, dua', Quran and Sunnah.
A corollary to this is not to blame ourselves for making mistakes.
This learning process is how Allah brings us along, making us more
sincere, smarter, wiser, and stronger. That's how we manage to do
better next time.
So instead of blaming yourself endlessly for past mistakes, use what
you've learned to build somethinggood and bright now, today, and in
the future./

--
:-> :->