Eyeshadows are a product that you will never stop buying, eyeshadows are like a drug for me! I like every color, texture, cream, pressed powder, EVERYTHING! But something I've learned throughout the years is that if you like so much eyeshadows like me, it's better to buy them in singles instead of palettes, and I'm going to tell you why.
Eyeshadow palettes are designed for people looking for specific looks that they will use everyday, or most of the time. That's why you can find palettes that only have warm tones, or very colorful ones, but rarely you'll find one that will suit all your needs. Although I do have several palettes, there's some that I don't constantly use. When I want to create a look I find myself using 2 or 3 palettes because some palettes don't have certain colors, etc. Basically from a whole 24 or more color palettes, you end up using the same 3 or 4 colors you loved from the palette, the day you decided to buy it. Palettes also tend to be more expensive than if you create your own buying singles; prices of a single eyeshadow can range from $5 to $20 dollars, but an eyeshadow palette can range from $25 to $300 dollars. Imagine buying a $300 dollar palette that you will be using only 2 or 3 colors to do your makeup?
Buying singles when you are a beginner MUA, or even when you already have a career is the most inexpensive and practical thing to do. You can buy empty magnetic palettes like the Z-Palette and have your favorite colors, and the ones you always use in a single palette. You can create your own, for example, I have a Z-palette where I only have my warm brown tone eyeshadows, from shimmer to matte, but only brown colors.
Some of the brands I know that carry single eyeshadows that you can buy and have a great quality are, Mac Cosmet`ics ($6.00), Makeup Forever ($17.00), Colourpop ($5.00), Anastasia Beverly Hills ($12.00). There's more, but these are my favorite ones.
I hope this was informative and helpful for you to take a better decision when buying products for your kit.