how can i decrease my rate of speech?

how can i decrease my rate of speech? I've noticed when I consciously reduce my rate of speech, my fluency is massively better. However, staying at that slower tree is really hard, particularly as my brain seems to work quite fast (I'll read really fast, process things really fast). Basically, how do y'all reduce your rate of speech? And is this a technique to achieve fluency that lasts for the long term?