Once we understand the normal balance of an account, represented by the image below, there is only one rule we need to know to make an account go up or down.
The rule to make an account balance go up or down is: do the same to go up and opposite to go down.
The rule of, do the same to go up and opposite to go down, may seem abstract at first but once we have the normal balance cheat sheet above it is easy to apply. The one rule means that an account with a normal debit balance will be increased by another debit because a debit is the same thing as the normal account balance and an account with a normal credit balance will be increased by a credit because a credit is the same thing as the normal account balance. Conversely, an account with a normal debit balance will be decreased by a credit because a credit is the opposite thing as the normal account balance and an account with a normal credit balance will be decreased by a debit because a debit is the opposite thing as the normal account balance.
Like most thing, the one rule is best learned through doing, by running through examples of transactions again and again.
Fortunately we have some examples of transactions here.