I've changed my tactics, I've become more of the sneaky poisoner archer type.
I carry 2 bows now, one sets targets on fire, the other steals their souls. If I see a strong looking target I add poison to the bow first and with the sneak damage multiplier it's usually enough to put them down or at least make them weak enough for a quick kill with the sword.
It's a tactic that doesn't work well with Mjoll, previously when I tried to sneak in places she would charge straight at the first enemy and slaughter everyone in sight before I had chance to draw my bow. She's also as stealthy as an earthquake.
With Aela I can sneak in places and if I want to go for the silent kill I can do while she lurks at the back ready to take down any one with a rain of arrows if I get overwhelmed.
A useful tactic is choosing when to level up, when you level up it completely restores Health, Stamina and Magic, if you are in a tough fight and low on life, having the option to level up mid fight can usually swing things back in your direction. Any skills learned do carry over though so you don't lose anything by not levelling up as soon as it's available.