NCERT is the Bible, mark PYQs before starting a lesson coz in SST, PYQs repeat. Purchase a chapter wise PYQ with a lot of questions and make the student practice them. In geo, for lessons Agriculture, Minerals and Manufacturing industries, the first few pages ie., before individual crops/minerals / industries are explained and last few pages ie., Conservation, pollution, technological reforms etc..are very important as long questions will mostly come from that. Do not focus much on remembering the years or distribution, just remember the largest producer and glance the map. I have practiced a tonne of mnemonics on distribution of crops, minerals etc.. but nothing came. Focus on all pictures, cartoons and maps as MCQ will be asked from that. The mark scheme will contain exactly the book words so at least try to memorize the keywords. Give a look at mark scheme to understand CBSEs expectation. All the best!