I came back to playing about two months ago and had very few CTDs. In the interim, I've installed quite a few new mods, including some biggies (OOO & MMM e.g.,). My machine must have got pretty fragmented with all the mod fiddling I've done. The defragger has been running for 15 min or so now and is only 4% done.

If defragging the machine doesn't seem to fix it, any other suggestions?

I know that TES4Positive has a lot of info about things to install when setting up your rig (most of which I did), but what about for continued maintenance?

The performance enhancements steps I currently have installed/running
1. computer always runs in safe mode
2. Game booster always runs
3. Windome Earle's Oblviion Crash Prevention installed
4. Stutter remover installed.
5. OBSE 18.? and BOSS
6. FastExit installed

Is it possible that any of those apps (such as weOCPS) should be reinstalled or something like that?

ADDIT: Wow. 1.25 hours later and I'm still at 50% defragged! I was pretty seriously fragmentated it seems. I'm guessing that will solve my CTDs, but still appreciate if anyone has any suggestions.

Remember to allow the computer to actually defragment on a regular schedule. My laptop is very sensitive about needing to be plugged in with the power on before it does its weekly defragmentation. Try and keep unnecessary files out of your data folder by using OMODS or Bain installation for mods. The CTD may be caused by just one mod or a missing/extra esp file.

Defragging, which took about 3 hours! Seems to have fixed it Thanks for the response bradleyh!