How can husband and wife help each other wake up for Subuh and night prayer (qiam)?

A couple who wake each other for prayer are helping one another towards the most blessed of good deeds. The Prophet ﷺ said: “Allah has mercy on a man who rises at night to pray and awakens his wife… Allah has mercy on a woman who rises at night to pray and awakens her husband…” (Sunan Abu Dawud 1308). Put the alarm clock away from the bed so you have to get up, and wake your spouse gently, not with harsh words. If one of you finds it hard to wake, find a way together without belittling them. Start with Subuh first before aiming for qiam. See prayer guide.