When it comes to rolling out the walls never ever use a cheap foam roller. Foam rollers never evenly absorb the paint out of the pan and will actually add time to you project and cause more mess. Buy yourself a synthetic professional 3/8 nap roller head for about $6 to $8. Not only will the paint be applied in a smoother fashion you will experience less work and mess.
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.
Store your leftover paint in plastic Rubbermaid beverage jugs or other plastic seal-able containers. Paint left in the can always gets funny after time. Either the can isn't properly sealed of it gets exposed to extreme heat or cold. I like to store my paint inside where the temperature is controlled.
Don't ask friends to help you paint. Basically, you are asking them to give up their day off to save you money. You don't want to be first on the list when your painting buddy hits you up to help him move do you?
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!
Suppose it rains while you're working? Vinyl paint dries fast - as quickly as 10 to 30 minutes - and will withstand a shower after that time. It takes another 12 hours to "cure," by then forming an exceptionally tough, long-lasting film that stands up well against weather, sun, salt air and factory smoke.
The area covered by a gallon of whitewash depends upon the nature of the surface, but ordinarily a gallon will cover about 225 sq. ft. on wood, about 180 sq. ft. on brick, and about 270 sq. ft. on plaster. The formulas mentioned will make from 10 to 14 gallons of whitewash. If a smaller quantity is desired, the amount of each ingredient should be reduced proportionately.