Credit cards... pay the billed amount in full before the due date every month. Never carry a balance that you pay interest on.
Utilities - always pay on time
Any credit - pay on time. Never be late or miss a payment
Mortgage - always pay on time, never miss a payment.
Credit in general - have some credit, but always pay on time and prepay when possible.
Home - don't move often
Never bounce a check - never have an NSF
Time - never having a negative with any of the above, and carrying credit successfully for a few years, you will likely have a great credit score. It is about behavior, not about your amount of income or equity - they don't necessarily have that info, and it isn't part of most scoring systems.
I have a low income, but have a perfect credit score. I don't use credit that I can't repay, but I am certainly offered a lot more credit than is good for me. I don't accept increases in my credit card limits, I never use more than 10% of my current limits.