painting is art and its not be that much easy to understand the methodology of painting, we are explaining the most common mistake which the painters do few of them below
while doing any touch up on the wall the main thing we have to look that once you apply new paint on old paint so dirty patch after that look new and rest of wall look different so better to do complete wall painting or else just used the good washable paint so you can easily wipe any marks
while you are going to filling holes of nails and other things you have to be very careful that put filler and late it dry then do sanding then no marks will be visible.people do paint while its not dry filler then after that marks more predominant next day which is really time hurting things.
painting ceiling have same issues if you apply paint on cieling then if you see closely you can found marks of ruler which is going right to left and its look so much bad once you have painted whole house, that time you cant see but you feel next day so you have to check all things and discuss with contractor
lady design paint now a days most creative and skill full paint.because of these paint introducing new ERA in paint texture paint,designing paint,marble paint,most great things.once you have done its brilliant while you are removing these paint could be very hectic if you didnt get good paint.filler and sanding most essential part of these paint removal so be aware painter do good filling in all walls if they do not do good all wall look so much hectic.