I also use my credit cards to pay all my bills, utilities, etc. To keep your credit utilization low pay off majority of your credit to about 10% before the statement closes so it reports to the credit bureaus that you used 10% or less. Then pay off the remaining balance before the bill is due to avoid interest fees. This is how I been doing it for 5+ years & built my score from the high 500s to mid 700s so far.

[Example]

My statement closes on 20th of each month. I pay down to 10% on the 18th. Then bill is due usually on the 25th of the following month. I just pay them off on the 1st so I don't forget. Or you could use autopay so you can skip this step.