i've never gone the prescription route, though i've been in your shoes before. one skill that i've built up over time is actually probably less a skill and more the understanding and acceptance that i have to work more than others to feel absolutely confident in what i'm expressing to a point where it's more "cognitive muscle memory" than actually having to be nimble and flawless at the same time. my best advice is to over-prepare. know your material and all the potential answers you'll have to regurgitate well enough where it takes the same amount of energy to respond to those questions as it does to answer "how was your day today?"