how do I know when to use Konjunktiv I or II when writing a sentence in indirect discourse?

When writing in indirect discourse we use the verb in konjunktiv I. However, when the Konjunktiv I is the same as the indikativ form of that verb, we use konjunktiv II.For example, the first person konjunktiv I of "haben" is ich habe, which is the same as the first person in indikativ präsens (ich habe) so instead of using KI we would use the KII form (ich hätte).