Getting a critique can be difficult especially when it is on a piece I've made and love. But praise rarely helps me learn how to improve my work or technique. Take serious musicians for example, they generally take private lessons from someone who is a professional and has honed his/her abilities on the same instrument as the student's. This instructor can hear and see what the student needs to develop and gives the student feedback and lessons (to practice) -- for the student's development.
Serious artists need to work at developing their ability and honing their craft as well through learning about the masters of their chosen discipline, practicing technique, developing their design sense, learning to play, growing their imagination and creativity, and getting honest feedback from 'professionals' in their art form.
So, if you are a practicing visual artist -- who do you ask for feedback (if you do), in what form do you get feedback on your work, and what form of feedback on your work do you prefer?
Critiques from others...those you respect for their expertise...are vital. They are as much a key to producing fine art as one's muse.