I cannot offer advice
to the budding artist
, or even professional help
to those with household painting projects, but I am offering what I learned. My goal was to paint table-like project made of plywood and 2x4's.
First, make sure to wear junk clothes (or just plain underwear or nothing at all if you don't mind paint on your skin) and use a drop-cloth to cover the floor, walls, furniture and other surrounding objects.
Second, make sure you have the appropriate tools, including a paint-tray, paintbrush, and paint-roller if you will be painting large areas.
I chose to paint the legs first, so I laid the table top-side down (on the drop-cloth of course). I then could sit in the middle and paint the legs (with the brush, because 2x4's are mostly too small for the roller). I made sure to paint the edges of the table-top because the paint helps to seal the wood (which will prevent later warping and slivers.)
I decided to let it dry before turning it over and painting the top side. That was a bad idea. As the paint dried around the edges, all of it that had dripped down served to glue the table to the drop-cloth. When I tried to turn the table over, I found that I had to peel away the paint and drop-cloth that were sticking together. After I eventually got the table turned over, there was a lip of paint running around all of the edges that had seeped underneath while it was still upside down. My sister and I had to use a putty-knife and sand-paper to remove as much as possible of that paint before I could paint the top.
My advice would be to set the table on blocks of wood while it is upside-down so that the paint on the edges will not act as glue on the drop-cloth or bubble unattractively.
It is also very important that any drops of paint (or drips of paint) be smoothed down before they dry. If a drop of paint dries, it will be a bump on your finished project, even if you try to paint over it.
If you are stuck doing a painting job in a garage or other hot area of the house, try to paint early in the morning when it is not too hot. I found that sweat which drips into the paint does not help it's consistency.
Using a fan to beat the heat is not necessarily a good idea as it can blow dust and dirt into the paint, which is difficult to remove without ruining what you have already done.
If you have long hair I definitely recommend pulling it back to keep it out of the way. I got some white paint in my hair and my family kept asking when I had gone grey.