...how do I go about increasing my income from my salary?
Do I need to hop around jobs looking for pay rises?
Looking at all possibilities apart from starting a side business because I have no interest in doing so.
With the constraint of no side business, you can either
a) find someone (other employer) to pay you more for what you do now, or
b) find something to do that someone (either current or other employer) will pay more for.
Path "a" typically involves job hopping.
Path "b" typically involves developing higher levels of technical expertise, or going into management.
What path appeals most to you?