Ways to improve your TOEIC score

Have a yearly study plan. Try a TOEIC test and analyse carefully what you got wrong and why. Write down all the things you will need to know and be able to do by the end of the year in order to get the score you need. Group those things together into categories (e.g. "reading skills" or "grammar"). Find out as many ways as you can of learning and practising each of those things and put them into your yearly plan so that the whole schedule has a lot of variety in it, e.g. by having different newspapers to read each month, or starting with local newspapers in English and working your way up to The Economist.