For me, I usually have some answered prepared in advance, but if I don’t have to answer in some form of allotted time (recorded interview questions), I usually take my time. Changing the tempo of my speech seems to work for me. Definitely relieves the stress of trying to get everything out quickly for the benefit of the other person, cuz if I do I’ll forget what I’m trying to say and completely mess up the question. For me when I get to blocks or repeated sounds or syllable I usually just stop completely, take a new breath and try again.