How to Reach 1200 Elo
You're past 1000, the basics are there. Now you need to see deeper tactics, learn basic endgames, and develop a thinking process that prevents blunders.
Two-move tactics
Upgrade from one-move to two-move puzzles. Look for check + fork, pin + capture, and sacrifice + recapture patterns. Build your pattern recognition.
Endgame basics
Learn: opposition, Rule of the Square, and Lucena position. These three concepts alone will save and win dozens of endgames.