Palette and cover
A glass palette is standard in indoor studios these days. Rarely do you see artists hand holding a wooden palette with a stylish berte hat like the oil painting cliché. A slick hard surface is much easier to clean and scrape dried paint films from. You can use any kind of flat glass as your palette. I'm really surprised the art stores do not have an over priced piece of glass marketed as the "essential oil painting palette". In my experience, I have found glass cutting boards work really well. They are typically a sturdy 1/4" thick piece of tempered/safety glass with smooth rounded corners and beveled edges. Glass cutting boards also come in a few different sizes, the largest being 20" by 16", which is what is pictured on my table. I found mine at Bed Bath and Beyond for about $10. They come with a smooth side and a textured side; obviously you want to use the smooth side. There are also some rubber feet that I think you will need to peel off the smooth side, and reattach to the other textured side. The rubber feet are nice to have to prevent the palette from sliding around on your table. You can glue them on using silicone glue, epoxy, or E-6000 glue - all of which can be found at the hardware store. I also made small notches in my table using a 3/8" drill bit for the rubber feet sit in. This eliminates any possibility of the palette siding around while mixing or scrapping dried paint.
The next step to preparing your glass palette for painting is to add a neutral color to the backside of it. I've seen some artist apply a medium brown color to the back of the palette, similar to the warm brown they tone their canvas with. While in school, I was taught to use a medium shade of gray - I think this a more common color. Some people will use a piece of paper under the glass palette but I like roll on a few gray acrylic. I picked up some Liquitex "Neutral Gray Value 5" acrylic and added a slight reddish tint with Alizarin Crimson to compensate for the greenish tint of the glass. The red will cancel out the green so the gray will appear more neutral on the top side of the palette. Typically 3 coats will cover the backside of the glass.
A glass palette will last many years and its ability to be scraped to remove dried paint film is a great advantage over a traditional wood palette. At any rate, the glass will eventually develop numerous scratches over the life of it's use. These can sometimes make scraping dried paint annoying because the scrapper can frequently get hung up in the grooves of the deeper scratches. At this point, its best to replace it.
I feel a cover is a necessary counterpart to the glass palette. Chances are you are going to keep mixes of paint on your palette for more than a day and you want to keep as much dust out of the paint as possible. Dust is constantly falling and settling everywhere and I hate when I see little pieces of fuzz in my paint, especially if it makes it way on to my canvas. Having a cover over your palette while not in use will help eliminate dust.
I made my 21.5" by 17.5" cover from a section of 1" by 3" piece of pine and clear acrylic Plexiglas. I decided to plane the 1" by 3" to a 1/2" in thickness for a slimmer appearance. Then using a table saw, I cut a narrow channel a 1/4" deep, the width of the blade, a 1/4" from the top edge (see the last picture above). I mitered the cuts and placed the 21" by 17" clear acrylic sheet in the channels before gluing up the four corners. The last steps were painting it and installing hinges in the back and a draw catch and handle in the front. I also added a piece of weather sealing on the bottom which made the cover fairly air tight.
If you don't have the tools to build a dust cover, you can always use a shallow cooking pan or a bin lid to cover your palette at the end of the painting session. These will work too to minimize dust on your palette. You will not be able to stop all dust from settling on your paints, but using a cover will help tremendously.