You scuff up existing paint for two reasons. First, you want to get rid of any oil, grease or dirt trapped in the top layer of paint. This is the stuff that cleaners and degreasers can't get off. The second reason to scuff is to set up a physical bond for the new primer and paint to adhere to. You want to give the old paint some tooth so the new sticks better. Repainting your house is a tricky business. Some rely on painting companies to do the job for you. Hiring the house painting service may also cost you. But if you are planning to paint it yourself, you might want to consider the basics; and consider the time and effort you will put on painting your house. Plastic sheathing and masking tape was not available at the end of the painting project for whatever reason, I have no idea, but you have a Paint Brush that if not cared for will eventually dry up. Last solution that works well, is to take a sopping wet rag, wrapping the Paint Brush up like that burrito you missed wrapping up earlier. This will buy you some time until either you use the paint brush again, or you can properly clean it.
To balance color, you must grasp the interconnectedness of color schemes. All color interactions are defined in the color wheel, and it has been used to build color schemes for centuries. There is still no standard labelling scheme for paint. The blue globe label, pioneered by B&Q, led to VOC reduction on the mass market and has been adopted by other brands, while the European Ecolabel, recognised in 15 EU member states, looks like a flower and appears on brands such as Earthborn. Germany also has a Blue Angel label and there is a green Nordic Swan as well. You will find more detailed information on most of the paint company's websites, as well as a wealth of practical and design advice. Materials and their application, every paint manufacturers paint will vary. If you are freshening up old walls and painting back to the existing color, the product doesn't have to be high end or have good coverage. If you need to paint a dark color over light color or light color over dark, you may want to consider purchasing a top quality paint to avoid multiple coats. I suggest Valspar, Pittsburgh or Benjamin Moore top of the line wall paint. These brands work well for straight out of the bucket use and are application friendly. Sherwin Williams is not my first choice because the coverage is poor and you will have to apply multiple coats but, it does apply, fluently. If you find a product does not apply well, maybe it is to heavy and/or sagging on the wall, you may need to thin the paint with a little water, this will reduce the coverage but make the paint flow better and lay down nicer on the surface. I do recommend latex paints for all applications, these days a good high end latex is as good as oil paint and your tools clean up much easier, it will also be less harsh on the respiratory system. The only situation I recommend oil paint, is as a primer/stain blocker over stains that "bleed" through the paint. You can get a stain blocking oil primer in a convenient spray can and spot prime any trouble areas before painting and in the case you need to prime all of the wall due to smoke or water damage, I recommend getting it in gallons and rolling it on where the stains are present. Don't forget proper ventilation and/or a respirator when using the oil based primers! Even if you don't need to apply a coat of primer before your new coats of paint, doing so will always save you money. Whether you use white or tinted primer, a coat of primer is always more cost effective for one simple reason: It is cheaper! In fact, primer may cost as little as half as much as standard paint. If you get it tinted the same as your paint, then it is cheaper by the coat. If you use white, as in the first scenario above, it will also minimize the number of coats of paint you have to apply. Either way it reduces how much paint you have to buy. Do you want to learn more about maximizing your paint color coverage, minimizing your paint usage, optimizing coats, and perfecting your primer?