How do I raise my credit score?????

Alright so my credit score is ok its at 745 atm but it went down 7 points from last month due to my bank declining a payment for my credit card and wasnt inform about it until a few days after the due date so when i repaid the bill it was considered late so i guess that dropped my score from 752...All year its been... show more Alright so my credit score is ok its at 745 atm but it went down 7 points from last month due to my bank declining a payment for my credit card and wasnt inform about it until a few days after the due date so when i repaid the bill it was considered late so i guess that dropped my score from 752...All year its been between 740 to 750ish and idk how to keep raising it...when i first started out it kept going up real easy but now im finding it harder and idk why i never miss my payments except for that incident i just stated...

Anyways is my credit still considered good? im almost 26 btw and started using credit cards since i was 22 and tbh as of now i owe about a little over $1000 between the 2 credit cards i have...those purchases were due to fixing my car and paying for my books and tution since i was unemployed for that month...i have an okay full time job so im trying to pay this off quicker putting in more in payments...anyways any tips on to keep my score good?

and also ive been thinking in getting a loan for a car do you think my score will be enough to get approve or should my dad co sign?
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