First of all ensure that your concepts are clear. Take a notebook and write only formulae of all chapters that are required to solve numericals. Practise derivations. If you feel NCERT has complicated the derivations, you may take help from SL Arora. Recommended Books - NCERT and SL Arora Try to solve all examples and exercise questions given in NCERT. You also need to solve 5-6 previous year CBSE Physics questions to boost your confidence.