They fell into several parts.
1.   Four basic vowel-type sounds
The objective was to produce them in a pure, open, relaxed and unrestricted tone in order to work out where your 'natural' voice was being produced in order to have control over it.
2. A number of singing exercises to handle different aspects of the voice. They consisted of:
Two short pieces of Wagner ('Tis Ended' and 'By Evil Craft') to help with the handling unfamiliar (small and large) intervals and unusual tunes accurately.
One short piece of Gilbert and Sullivan (Rising Early in the Morning; from The Gondoliers; but similar G&S will do) for precise articulation while singing at speed.
One piece of Mouth Music (Tail Toddle - 2 choruses and one verse sung in one breath) for speed and articulation also breath control (sometimes Rocky Road To Dublin was substituted - one chorus and one refrain sung in one breath).
These can be memorised in a week, once learned, never forgotten, still can do most of them after forty years, though breath control is not as good as it was (takes at least 2 breaths for Tail Toddle and Rocky Road nowadays)
3. Series of relaxation excercises (neck, shoulders arms, back, legs) to help control tension (starts off as full exercise, but once mastered, full exercise is seldom needed and tension can be contolled wherever it appears) Probably the most useful work I was ever given; can help with activities other than singing.
All the exercises came with full explanation of their purpose and uses, along with a breakdown of the theory of their necessity.
They might sound complicated, but they come automatically once learned.
Jim Carroll [ Quote]above.
When one sings the diaphragm should be used, thus breath control is stronger, a little ornamention is a spice of added interest when there is no instrument, singing from diaphragm there will be no dead air