Sometimes if i have a history of blocking over a certain word, i try to change the words in front of that word. Like instead of simply saying “name”, i might say something like “hi, my name is name” so I'm not saying that first constant (for me B sound ) B first. I'm burying the “B” and that's what works for me. If you know you will block over something no matter what then, try this breathing technique. Take a breath in, slight exhale (it will relax your vocal cords) then speak. I hope this helps