I'm somewhat 50% into the game. I've done a good portion of the main quest and have done a lot of side quests in major cities as well as completing the Thieves Guild and Companions. Now i'm stuck, im not sure if I want to finish doing all of the side quests first or finish the main story then do the side quests.

I remember in oblivion, I did everything there was to do in the game including expansion packs and then finished the main quest last and regretted waiting because i didnt even use the armor in the end because it was weak.

I wan't to go ahead and finish the main quest because its getting really good now but i'm afraid i might end up voiding certain quests if I end up finishing it. The same thing can go for the civil war. I know certain events in the main quests can end up changing things in the game
basically what i'm asking is there anything i should do first before going into main quests and civil war. I dont want to end up finishing them and end up regretting it because i can't do a particular quest anymore. thanks for the replies.

I just make sure to visit all cities before moving up on the main quest. From there i can decide without delaying the final moment too much.

I was kinda hoping to save visiting the smaller cities after the main quest so I can save some of the surprises.

Use the other thread you have; Spoilers is the better forum for this.