I use the non-stick cooking spray not for protection, but because the paint all over my hands is easier to clean off. When I'm finished working, I just wipe my hands on a towel, then a bit of soap and water and my hands are clean. Sometimes paint on the cuticles, or under the nails is hard to get rid of.
Here's a couple of other things I've found useful:
Add food coloring to you gesso. It cuts the glare of the canvas when you first start, then acts as a middle tone. Its also useful in laying down full, even coats of gesso onto your support.
papertowels are often useful; use a short bit of twine tied to a stick and dropped down the tube. Tie the other end of the twine to your easel in a handy spot. I generally put a light rubber band around the end of the papertowel roll to keep it tidy.
When gessoing panels, nail them into frames to dry. This prevents warpage, except on very large surfaces where traditional gesso "all-round" is still advisable.
Turn the surface upside down, check it in a mirror, or hanging on a wall with a lot of other pieces between painting sessions. This helps to identify where things are going wrong. It is a way of divorcing ourselves from the vision we have created in our imagination.
When painting from an object, don't look directly at it for long periods. Keep the eyes moving. To focus too long, just a matter of seconds, will screw up your ability to correctly "see" the color and tone.
Painting is a form of meditation. Do it often, preferably everyday. Keep three of four paintings going at a time, and move back and forth between them. This lets the surface of the pigment dry enough for the next layer of paint. It also helps to restore our rational critical facilities.
"More paint is almost always better than thin paint". Light doesn't just bounce off the surface of things carrying with it their colors. A small portion of each light wave penetrates to a lower pigment layer. In bouncing from the object back to the observer, the light frequencies are altered by passing through each layer of paint. If you are painting with relatively transparent glazes there will be greater frequency changes because more light is altered as it journeys through the pigments. I paint almost as much with light, as I do with pigments.
A lot of folks tell me they dislike oil because of its drying time, and they aren't wrong. A moderate amount of pigment will take, in most moderate climates, up to six months to fully dry ... that's why varnishing is generally done six months to a year after the paintings last work. However, I schedule sessions only a couple of days apart. Starting a session, I wipe a light coat of oil over the whole surface. While thats being done, I let the brush(s) that I will be using sit in oil to loosen them up and grab hold of a store of oil. The oil on the surface reduces the amount of oil/turp/mediums I need to use on the palette. It also "loosens" the paint from the earlier session just a tiny bit. That makes it easy to use "fat" colors to blend into the older paint. The result is a more even and better rendered final product.
Since many of you have formal art training, I suppose you already know most of that. It may be useful to the occasional painter.