Utilization is a snapshot. When I apply for credit, I see an inquiry on my credit report which lasts for 2 years. Depending on my score, there's a ding to the number which may or may not really matter.
Utilization, on the other hand, is based on the current cycle. One month, I paid my card in full, the day before the cycle closed. Zero utilization. Lost 15-20 points on my score. Next month it was back. I recently took a zero interest advance which was sizable, pushing my utilization above 30% and trashed my score. When it's paid back, the score will recover.
Per the comment, below, note that utilization is calculated from the balance on the statement. A payment before the statement is cut can make the reported balance be zero, or a number that in the range you wish, depending on your payment amount. (thanks, Eric)
In your case, first, if you are not applying for a new loan, whether it's buying a car, house, etc, or just getting another card, your score doesn't really matter. Obviously, you don't want to pay late, or do anything that has a lasting impact, I mean the slight variation that utilization impacts the score.
If you still wish to be score OCD (not judging, many people just like to go online and see a shiny 800 every week) I'd pay the card in full, never pay interest on a card, but use it every month. Unless your grocery store discounts for cash, just use it there, or for gas, etc, and pay it in full. The ideal number seems to be just under 10%, per this graphic from CreditKarma
For what it's worth, if I drop my utilization back to normal, under 10%, this is my predicted score -
Funny, though, a simulated drop to zero boosted it further, to 831, which contradicts what the site said prior, that zero is worse than just low, regular usage.