You can try speaking with less tensions onto your articulators in front of people. For example, to pronounce 't', don't tense up your tongue to hit the gums vigorously and just be delusive like you don't have a tongue and put your tongue gently close to the gums to pronounce 't'. To pronounce 'b', don't collide the lips seriously and just put two lips gently very close to each other to pronounce it and maybe you gotta practice and practice to grasp what I am teaching. For more info, you can check my last posts about Gentle Speech and I hope I can help u a lot :)