1.  Have a mission in the first place – so set yourself some new objective
2.  Be enthusiastic about your mission – this helps when the going gets tough
3.  Tell others about your mission – then you get some moral support and someone who will check up on you!
4.  If its a long term mission – make sure you have some short term milestones to keep you motivated
5.  Remember that most people cannot achieve things on their own, we need other people, so identify who   will be in your team to do the things that you are not so good at, or interested in.

Then go for it and see what happens!