Always dress the weak or affected arm or leg first. In your father’s case, dress his right arm first. Then dress the stronger arm or leg. When removing clothing, reverse your steps. Take clothing off the strong side first.
Be sure you are not rushing her to dress. Also, try to follow the same routine each day so she does not think dressing is some new activity. Give her short and simple instructions as you help her dress. Respect her sense of modesty. If a task is non-essential but causing agitation, let it go and try again later when she is in a different mood.
Thick, rough, or stretchy fabrics make it harder to don or remove clothing. Lightweight, smooth fabrics are much easier to slip on.