You must not skip a payment even if you plan on paying off the entire outstanding balance next month. When you originally obtained revolving credit (credit card or line of credit) you agreed to make the minimum monthly payment.
Keep your balances under your credit limit.
Keep your credit card or line of credit balances below 75% of the authorized limit. Many individuals who have never missed a payment have low credit scores due to their utilization rate (the amount of credit used vs the authorized credit limit).
Don't apply for new credit or close existing credit unless it's absolutely necessary.
New credit can decrease your credit score and label you as a credit seeker. Closing existing credit can also affect you negatively as it could decrease your overall tenure of repayment.
Pay off any collections or late debt.
While a collection or late debt is never good for your credit score, remedying the situation is the first step to increasing your score.
Get old negative information removed from your credit report.
Negative information (collections, judgements, consumer proposals, bankruptcies, etc.) can stay on your report for up to 10 years depending on your province. If your report is still showing negative information that should have been removed by now, you can contact the respective credit bureau (Equifax or TransUnion) and ask for that information to be removed.