am repainting the living room ivory cream crown matt emulsion...can you pros advice me on all the prep work before applying top coats ? do i need a mist coat still as its not new plaster..also there are several cracks in the plaster mainly around the area where the old dining room door has been boarded up! what is the best way to repair cracked plaster/board etc as ive tried to fill then sand them when did the bedrooms but the cracks keep reappearing! very frustrating tbh cheers again