Blender | Move camera while looking through it

It seems the best way to do this in Blender 2.8 is by while lookng through the camera you want to move pressing shift + `(shift + f in 2.79). This will put you into an fps mode where you use w, a, s, and d to move the camera around. Alternatively you can move the perspective view around until you get a decent angle and then press ctrl + alt + 0 and that will position your current active camera to the current position of you perspective camera - although this doesn’t seem like the most precise way of doing it since you can’t seem to change the focal length of the perspective camera to get an accurate representation of where your render/active camera will be/what the frame will look like.