Most couples give up on praying together because they start too big. Begin small enough that you cannot fail.
Choose a fixed time attached to an existing habit: after coffee, before turning out the light, or in the car on the way to work.
A five-minute structure: one minute of silence, two minutes of spoken gratitude, and two minutes of requests, each person praying for the other.
Write down what you prayed for. Reviewing answered prayers fuels a couple's faith. If one person is not well enough to pray, the other can pray aloud — and that is enough.