...start by doing little things well now. So says Jesus Christ when describing the 'reward system' that will be operative on Judgement day:
Well done, good and faithful servant! You have been faithful with a few things; I will put you in charge of many things. Come and share your master's happiness (Matthew 25:21)
Notice that the servant is not commended for having undertaken a prominent or distinguished role or for even having done lots of things for Christ. The praise comes for being faithful/truthful/reliable with a few things. So if you want to achieve great things for God, first get your to do list and shorten it then do the few things well - turn up when you say you will, following through on the things you commit to doing, pray and read your Bible regularly, speak about Jesus often, forgive those who have hurt and wronged you, walk the dog with joy, change the nappies with cheerfulness, eat your food with thanksgiving. There are probably one or two other things you could add but that's a good start. Faithfulness in the small things will guarantee being praised by the King of Kings.