Practical posts give direct, actionable advice on how to achieve goals and generally succeed.
However, material which is directly about how to think better can be found at Rationality.
These topics are either central or high-quality.
Productivity
Motivation
Communication Cultures
Conversation (topic)
Meditation
Scholarship & Learning
Financial Investing
Akrasia
Cryonics
Goal Factoring
Pica
Relationships (all kinds)
Slack
Spaced Repetition
Willpower