Tips to brain crush more often

[Magus]

I'm struggling to brain crush on most enemies that don't have a shell. I know that using follow up attacks and elemental stuff is helpful, but I tend to kill stuff before I get the crush gauge down. I don't have this issue with shelled enemies. I attack weak points and throw objects at them whenever I can but it doesn't seem to help much. What am I missing?

I'm on phase 5 with Yuito by the way.

[Blendi]

Just varies somewhat from Other to Other. As you you said you dont seem to have an issue with those that you break their shell. Some Other's crush faster when you hit them with PK attacks(chucking something at them) and others crush faster from shock, pyro etc.
But there are powers that boost crush dmg as well as items. Clairvoyance and Invisibility both boost crush dmg. CLairvoyance is easier to use than invisibility(dont have to use the backstab just attack/pk attack from invisible will work wonders too) but both together can make crushing really easy.

[homonovas]

Try to use crash augment.
And chains attacks with fire/Electro on attacks

[Fabiaville]

using psycho follow up attacks and imbue attacks with fire/elektro. though i wouldn't worry too much about brain crush up until you get the powers of kasane's platoon.
then you can use duplication in addition to clairvoyance and elektro. you'll shred through crush gauges most times with this (remember to upgrade their bond level).