I perform a lot of laser microdissection, in which relative few cells are collected for RNA extraction. I use the RNAeasy microkit from Thermo (https://www.thermofisher.com/order/catalog/product/AM1931), which seems to work well. Your isolation method may depend on what your goal is following extraction. Are you performing single cell qPCR, or next generation RNA-seq?
Please see my question thread, it might guide you for the best way. In my case I have used both heating at 95C and RNA purification kit. Also I tried trizol comined with using columns to purify the RNA.