IB Chemistry rewards the student who nails foundations in the first three months. Miss those, and every topic afterwards feels harder than it should.
1. Stoichiometry is not a topic, it is a language
Every paper depends on fluency with moles, concentration, and ideal gas maths. Students who still pause to convert grams to moles in DP2 have lost the plot. Drill it in DP1 until it's automatic, then forget about it.
2. Learn the examiner's command terms before you learn the content
Define. State. Describe. Explain. Discuss. Each carries a specific mark allocation and a specific response shape. A student who writes a long answer to "state" is leaving marks on the table.
3. Maintain a mistakes book, not a notes book
Your notes will never be as good as the textbook. But a personal log of every question you got wrong (with a line on why) is the single most valuable study artefact you will build. It grows with you and catches the same trap twice.
One note on the practicals
The IA counts for 20 percent. Students underinvest in it because it is not an exam, and then get surprised by a Grade 5 when their papers were Grade 7. Take the IA seriously from the moment it is introduced.