What strategies help CSOs achieve long-term financial sustainability?

We’ve been operating for seven years and we’re still almost entirely dependent on one government grant that gets reviewed every year. Every year around renewal time we’re holding our breath. I know this is a risky position to be in and we need to diversify but every time we try to develop new income sources we get pulled back into delivery and it never happens. What strategies have actually worked for organisations in a similar position? And how do you find the time and capacity to build sustainability while still running your programmes?