"연습해 보시고요 / 연습해 보세요"
보시고요 here doesn't mean anything specific but just smooths the ending leaving a nuance of something continuing.
It is a bit like "You (can/will) practice it (and we'll go from there ...).
연습해 보세요 sounds like a direct order, so people tend to avoid it unless it's really necessary.
The ~고요 form is particularly useful at places like a hospital where they have to give instructions constantly:
이리로 오시고요, .. 다음에 여기 올라서시고요, .. 숨을 크게 들이마시고요, .. (You want to follow me, .. step on this thing, .. inhale deeply, ..)