Once your breath is free and relaxed and the pressure is reduced from below your true vocal folds now you can release any pressure above or throughout the folds themselves.
Here's some basic vocal anatomy first:
Often, when we are straining at the level of the true vocal folds we are squeezing in on them from just above in the false vocal folds. This happens naturally when we swallow and cough, but when it happens when we are singing it can be detrimental either immediately or over time.
So, what can you do?
Here's a taste of some Estill Voice Training:
1. Get to know what Constriction of the False Vocal Folds feels like. Constriction of the FVFs is when the FVFs are squeezing inward. When we are breathing quietly our FVFs are at rest. In Estill terms this condition would be Mid. When we wheeze they are squeezed inward (Constricted). Alternate between breathing quietly and wheezing. Where do you feel the movement in your larynx when you are wheezing? Can you feel it release when you go back to breathing quietly? Now, try it with sound by beginning with breathing quietly then adding tone (without changing anything else in your larynx). Then, wheeze and keep the wheezing feeling while you add tone. This may feel quite uncomfortable*. Don't do it too much or with too much force but just enough to feel and know what it's like to Constrict the FVFs and release the Constriction to Mid.
2. Learn to do the opposite Retract The False Vocal Folds! The FVFss move out of the way of the true vocal folds when we are about to laugh and cry and when we are breathing absolutely silently (you can stick your fingers in your ears and when the false vocal folds are pulled out of the way you won't hear anything!). This is FVF Retraction. Keep the feeling in your larynx while breathing silently as you add tone. The sound will be a bit fuller, clearer, more resonant and will feel like there is no pressure on the True Vocal Folds at all! Aaaaaaah! Happy vocal folds!
*Make sure that your breath stays easy beneath the true vocal folds while you explore these movements in the false vocal folds! If you feel like practicing squeezing them inward is causing trauma (tickle, cough scratch, hoarseness), leave it and practice the opposite!