I'm curious to know what some other players' takes are on some issues I am having with continuing on with my character.

I have completed the main quest, found some 200 locations - most of which I've cleared. I have smithing and alchemy up to 100 skill. I am just about to hit level 51, I'm wondering about a few things....

First off - is there an easy way of improving some of the things I have not leveled up? For instance, I am mostly a dual-wielding melee fighter with restoration magic, a pretty standard easy-to-use character. I have pretty high archery and pretty high heavy armor skill. I am playing the game on Master difficulty, and it still seems rather easy to completely blow through whatever I want - which is fine, I have no gripes about it. I am wondering if there is an easy way of leveling up things that I have not used, say for instance Conjuration or Alteration, Destruction or 2-handed weapons. I'm just wondering because basically if I try to use any spells I get destroyed, so it'd be nice to level it up since that would also help me gain some levels. In other games, take FFXI for example, if I had a character that I wanted to level up something like that, I could take it to certain areas and power level it basically. I could go fight easier mobs to level it up through the lower levels, and as it got higher move to different places. Is that possible in this game?

So would it be possible for me to become adequate enough with conjuration or destruction so that I could actually use it - or would I simply be better off just making another character and focusing more on being the opposite kind of character that I currently have?

I also feel like I am running out of things to do. I have plenty of quests, but some of them I seem to have broke? For example there's a quest in which I am suppose to find 30 Crimson Nirnroot. I happened to clear the place that had all of it prior to getting the quest, and used a lot of the nirnroot in potions or selling it, maybe even dropping it, who knows, the quest says I have all 30 when I really only have 7 because of this. I went back to this place in an attempt to gather more and I could not find enough. There is also a quest in which I am suppose to find a Forsworn heart, I have one but it will not let me complete the quest. I have all of the items needed, but it continues to tell me to get this heart I already have and won't let me drop it to obtain another. Is this some kind of bug or am I missing something??

All in all I love this game, but after completing the main quest line it seems as though everything else seems to be lacking. Can anyone give me some tips (not spoilers) on things I could check out or aim on completing? I'm trying to breathe some new life into this game for myself. I have not played it in about 3 weeks but I'd like to get back into it and pimp out my houses and things like that. What kind of stuff are you other players doing that allows you to enjoy the game post-dragonslayer? I'm interested in hearing what you guys have done that maybe I haven't as there's so much to do. I mostly like to find things out for myself but right now I just feel lost with my character, I walk everywhere to try and explore as much as possible but I just can't seem to find anything very interesting.

Get a horse and spam soul trap on it to increase conjuration super-fast.
Get the muffle spell and spam it to increase illusion.

If you want something that feels less like power-leveling.

You can put away your dual swords or whatever and start using bound battleaxe... that will quickly increase your 2-h and conjuration.
Swap your heavy armor for light armor.
Pretend your character is having a second youth, and go become a ful-out mage in Winterhold College (just make sure you have some proper enchanted armour, because if you've been a melee-heavy armour up to this point then going with simple robes and no mana will be a disaster)

That's actually pretty good advice, thanks

Roleplay an explorer/cartographer and go find any locations you have missed in your playthrough [that's actually how I saved my character from boredom and depression ]. 200 locations discovered means you have still plenty to discover. Total locations in the spoiler.