SaThere are two aspects in getting higher yields - First, using effective inputs like high yielding variety seeds/hybrids, using growth harmones etc. This can't be done by farmer. It requires lots of infrastructure, time, knowledge, skill in developing the varieties.
Second one is cultivation practices (I hope you mean this as crop production will cover mostly the cultivation practices). This again differs from plant to plat as every plant has different crop cycle, specific nutrient requirements, specific pest and disease to manage etc. By practicing Integrated Nutrient Management, Integrated water management, integrated pest management practices one can get higher yields.
I'll try to explain with one example. Paddy cultivation - through transplantation.
Follow transplantation instead of direct sowing/broadcasting - S.R.I method is proven highly efficient - uses less quantity of seed and plant become robust.