Tips for Efficient RNA Extraction from Difficult Samples

I've been trying to optimize cytokine detection in our PBMC culture supernatants, but I'm honestly getting lost in the sea of ELISA kits out there. So many brands claim high sensitivity and low background, but when it comes down to actual performance, it's a different story. Does anyone have firsthand experience with kits that are consistent and not a nightmare to validate every time? Preferably something that doesn’t require an entire day to set up and troubleshoot.