I use,
1. Bound Sword or an offensive Spell.
2. Main offensive Spell, or a Ranged attack. This is where My Destruction Spell goes
3. Healing. I began with 1 for Melee, 2 for Ranged, 3 for Healing from prior Games.
4. Flesh Spell
5. Cloak Spell
6. Alternate Element for 2, or an Atronach
7. illusion Spell. Usually Muffle.
8. Summonings not on 6.
the Q button on a PC will bring up a list of Favorites, but the Favorites do not need to be assigned to a Hotkey. I keep Transmute, Equilibtium, Heal Other, and Necromantic Healing (Serana needs help sometimes) and I like to have a Novice Spell to use if I am running low on Magicka. Backing slowly away from an opponent while hitting them with a short burst of Flames every second usually will kill most enemies before they kill Our character.