Thought I'd share some of mine, but also would love to hear those of others. Of course, everyone has different play styles, so most strategies change
depending on whether you are a melee guy, magic guy, or archery type.
While you can only have one follower at a time with you, if you've gone far in the Dark Brotherhood Quests, you can also summon the Ghost of Lucien
LaChance (and he won't count as your follower). You could also summon something to fight for you in addition to this, if you are magically inclined
(I'm not, I'm a stealthy assassin archer type).
One reason I don't usually use the followers, is that they will give me away while sneaking, etc. However, with the Dark Elf Assassin gal in
Whiterun, she'll go stealth when you do, and if you give her a bow, and one good arrow, she'll do missile fire as needed also. I married her, so
that I don't have to pay her 500gp each time, hehe...
MAD GUYS AND ARROWS
I've noticed that many foes sometimes get tripped up by ramps, stairs, walkways, etc. and if you are close to them (just barely out of melee reach),
you can arrow them until they die, all the while they try and swing at you, vs. trying to actually go the path and get to you...
FOES AND FALLS
I just love using my dragon shout to knock somebody off a cliff to parish on the rocks below. Don't do this on someone you want to loot though,
unless you're up for a long climb and search.
I've found that with my female follower, and the summoned Ghost of LaChance, taking down dragons isn't too bad, especially if I fast travelled to a
non-walled settlement. The nice thing there is, some guards will likely help with the dragon (or at least serve as targets for the dragon). Often,
there are also porches that can help keep you from getting the brunt of the breath weapon,
POTIONS POTIONS POTIONS
Fast way to heal up in combat, go invisible, paralyze foes, etc. Nice thing is, unlike Oblivion, you can make these right from the get-go, as long as
you know what ingredients make what. Most are pretty common too. I carry a bunch of these.
I can spot traps well (and have the Sneak perk that keeps me from triggering pressure plates in case I don't see them). However, I love using these
on the enemy. Put an arrow into one to get them mad at you, and have them run right into existing traps. Fun to watch.
I noticed that many of the items on the shelves are there for the taking (i.e. they aren't stolen). Check this, if you haven't caught it before. Of
course, I then come back at night and still rob the place of the potions that counted as stealing.
Early on, the chests in the thieves' guild have some decent stuff in them, free for the taking (not stolen), like potions, magic items, gold, etc.
PARALYZE, HACK, REPEAT
For really nasty hard-hitting foes, I'll often do a stealth arrow attack with some Paralysis poison just before they get too close for comfort.
Either use more arrows or switch to swords and hack...then fall back as they get up, treat the next arrow or my sword with more paralysis poison, then
go to work. Especially nice for Trolls who hit hard. I haven't been brave enough to try with Giants yet though. I typically leave them be, so far.