When I started painting, I used the cheap plastic trays with multiple cups as a palette. And soon discovered that the tiny amount of paint they hold is mostly useless and they are hard to clean. I then switched to the wooden gesso coated palette boards. It worked mostly well, but it was hard to leave it on a surface while painting. It felt like I have to hold it!
Once shopping in Ikea, I found a large window piece with glass that worked really well as a palette. I just left it on top of a cabinet by my easel, it was easy to clean with a spritz of water and a wipe with a wet sponge. However, if I forgot to clean right away, it was messy to move it to a sink and give it a full wash.
Recently I found a stack of 12 porcelain dishes - pasta bowls that I have been using for the last 2 months. One of the best finds ever! They are awesome in letting the colors stay true as I mix, I can either hold it or leave it on the table and the best thing, they are easy to clean even if the paint has completely dried!