Obviously the first step is to BOSS and BASH your mods if you are using a lot of them, however even after that, I was having a lot of issues with crashing, etc.

The following has pretty much ended all CTD's for me:

1) Download the new alpha SKSE with Sheson's Memory Patch built in and make sure the .ini settings are setup right

2) Download Optimizer Textures and run it with the minimal(safe) profile on all textures and BSA files. This compresses and optimizes the textures with little to no loss visually. With my mods, I saved roughly 1.4 GB of space between the compressed and optimized files and the original files. Make sure the "make backup" box is checked so it will automatically back up the originals before overwriting them with the compressed and optimized version. It seems that huge textures are a big cause of CTD's and this helps tremendously not only with that but also with stuttering/freezing.

3) Safety Load, while many bash it, has completely stabilized my game in conjunction with the two above mentioned things. Instead of getting stuck at an ILS, it might take a while but it continues to load and has not crashed once on me.

Doing these three things has pretty much made my game rock solid stable...never thought I'd say that with skyrim.