Make music with other musicians whenever you can
Get involved making music with other players whenever you can. If you are a pianist, play for a singer or with someone learning an orchestral instrument. If you are a string or wind player there are so many wonderful duets, trios and quartets you can play. Join a choir. You will learn ensemble skills, how to phrase and breathe with other players and singers, and gain a knowledge of how your part fits into the whole. Again, musical awareness and sight-reading can be developed significantly by making music with others.