As also a music teacher, I am always on the lookout for good music sheets that students would enjoy which also teach great technique. The following two links are such a source. These have worked well for someone who has already learned some hymns or is advanced enough to read intermediate level hymn arrangements.
Two favorites:
Come, Thou Fount of Every Blessing – Level 3 (I have had students play the first page through two times.)
It Is Well – Level 3
A special “thank you” to Michael Kravchuk for his work and having these arrangements available on his website.