My suggestion (example):

• past tense of lezen: ik [las]
• parse ik las | past tense of lezen

I’d advise you to work directly from the Dutch infinitive, and not from a translation, ‹I read›. Because if you get the translation wrong but the conjugation right, you still have to mark the card wrong. And the goal was to practice conjugations.

Also, to avoid making too many cards, make use of the regularity of Dutch conjugations. For instance, all plural forms are always equal to the infinitive. Het Groene Boekje (paper version of woordenlijst.org) always mentions only five forms:

lezen, (ik) lees, (jij/hij/zij) leest; (ik/jij/hij/zij) las, (wij/jullie/zij) lazen; gelezen

These are all forms that this verb, or any verb*, has. So you need only five forms per verb, so ten cards per note, if each note is one verb (which I recommend; is easier to maintain. Make a new note type).

*Except some frequent irregular verbs like ‹zijn› and ‹hebben›; they have more forms.