The most important quality in both practices is to be "relaxed", meaning no unnecessary tension in body and mind.
Asking yourself in your mind "what is the next movement again?", wondering whether one really executes a movement the way it should be done, trying to hurry thing along, etc. is creating tension in one's mind and this will reflect in one's body.
Forcing oneself to perform a movement picture perfect even though one may have an injury and can only do so with pain, is creating tension in the body which reflects in the mind.
Remember the 70% rule, only do things to 70% of what is possible. Practice will move you forward, today's 70% would have been yesterday's 80% and last week's 90%.

One of the best practices is to just stand in the Qigong stance. See how far you can "relax", observe where there is unnecessary effort and see whether you can let go of it, but do not force anything. You will feel manifestations of Qi fairly quickly.
Yeah, standing can be a bit boring and it goes against our western idea that we should be able to do something about anything, including getting Qi to flow and feel it.

One does not have to be perfect but one should strive towards the most excellent execution possible at the time. This will be different for beginners and more advanced practitioners, it will even be different from day to day, and "relax" also applies here. There is no place to criticize oneself when today's practice feels out of sorts compared with yesterday's.