Remove furniture/ornaments etc from the room
The last thing you want to be doing is having to reach around breakables and/or awkward pieces of furniture. So move what you can out of the room and move larger furniture such as sofas into the middle of the room to give you enough space.
Cover floors and remaining furniture
Accidents happen so dust sheets are a must for covering flooring and furniture.
Remove wall hangings
Make sure that you leave the holes for hanging your pictures and mirrors back up again. Don't forget to also, loosen light switches and plug sockets - painting behind these rather than around them gives a much more professional finish and disguises any paintbrush marks.
Clean the walls
You can use sugar soap and a sponge to get rid of any dark marks and stains. Repeat with just water and let your walls dry fully before painting.
Tape along skirting boards, window & door frames
This helps ensure a neat and professional finish. Masking tape peels too easily and can make your job more difficult, so invest in good quality painter’s tape to keep the paintwork tidy.
Prime your walls
If you are painting on a newly plastered wall you will need to prime your walls. It's also a good idea to prime your walls, If you are changing the colour from dark to light, the previous coat is glossy etc. A few layers will most likely need to be done especially on newly plastered walls.