In my opinion, you are very well placed for a FICO score in the lower 700;s.
No derogs (reported 30/60/90+ lates, charge-offs, collections, or public records) place you into position for moving into the 750+ FICO scoring bracket.
% util is one of the few FICO scoring categories that has no historical memory. If you go from, say 50% one month, to <10% the next month, FICO looks only at your current monthly % util.
You also have multiple lines of credit mix, with two installment accounts in addition to your revolving account.
To break into the mid-700;s or above, you usually (not always) have to have multiple established revolving trade lines. FICO puts much more emphasis on scoring of revolving lines of credit (CCs) than on installment accounts. You may still be considered to have a "thin" credt file, making it hard to break into the higer FICO scoring brackets.
But to do this, and thus build for the future, you may have to bite the bullet, apply for at least one major CC, and take the hit with both a new inquiry, and a reduction in your average age of accounts. If the new card has a good credit limit, then improvement in your overall % util might immediately offset those impacts in the other FICO categories. No simple answers
Since FICO does not publish specifics of their scoring algorithms and bracketing, it is kinda hard to give firm short-term advice.
I doubt that there is much that can done in short term measures to leap into the 750+ score range.
If your sites are set on longer term FICO score improvements, then I suggest getting an additional major bank card.
Derog is short for derogatory, as in something negative that counts against you.