I must be doing something wrong - I'm level 25 and I'm getting smacked around a lot when I enter the miscellaneous dungeons and keeps. I've focused on 1-hand, light armor and destruction. I also spread my perks out in some pickpocket, stealth, 1 point in restoration to make the healing spell cost half as much, and a couple in alchemy to make better heal pots. My strategy is to sneak up a little and open with a critical hit with a poisoned arrow with my elven bow. Then I switch to my skyforge 1-hand sword and rely on my elven armor set to keep me safe. Sometimes I'll use a shield but usually I have a spell in the off-hand like flames. I don't have any trouble dropping a single opponent but when there are 2 or 3 they close on me - I usually try and have a flame rune between them and me and I have Lydia with me tanking and sometimes a flame atronach summoned. They drop Lydia in 4 or 5 hits on normal mobs or 2 hits if they are a "captain" type. They drop the flame atronach in a few hits. Then each hit on me takes between a 1/5 of my health and as much as half if they are a "captain" type with a 2-hander. I'm drinking heal pots like they are going out of style, trying to position myself in areas they can't hit me, and it just feels like my 1-hander barely pokes them.

I'm trying to play on just normal difficulty. I did knock it down a level but then it is so easy there is no challenge. I know a lot of you guys are tearing it up on Master so there has got to be flaws to my strategy.

You're split between four offensive (archery, one-handed, destruction, and conjuration) styles and you have minimal synergy. You're way too spread out.

To put this in perspective, the only offense you lack is two-handers.

Hows your smith skill upgrading your weapons and armor can help in the long run and give Lydia some health potions so she can stay in the fight longer

Yeah, I'm level 21. mostly Archery, Sneak and Two Handed. So when I do have to have a melee combat, my health depletes like no other because both LA and HA are in the 30s. But I can kill most top bandits and mages within 2-4 hits. It is definently getting tougher as I go on.

I don't have any perks in Archery or Conjuration. I bring up the atronach because it is a free helper and I can get that mana investment back before combat starts - same principle as the flame rune, I cast it then let my mana regen before I start combat. Once combat starts I don't use archery or conjuration any more unless I see a situation that calls for it. I primarily rely on my light armor to take some hits while I strafe around and my 1-hander to deal damage. But when I go against a foe that has decent armor my 1-hander doesn't do much damage. And my light armor cannot take blows from a good enemy with a 2-hander so if I find myself backed into a corner my only options are to chug those heal pots or if I can blast them with my shout to knock them back and run. Running gets boring.