Supplies are very important to making an look appear real. While supplies can be expensive there are ways to cut costs. I'm going to go over what I have and use while telling you were to get it or to get things that work as well for a cheeper price (as well as easier to come by).
I have a wide selection of liquid bases in varying colors. This is because my skin tone varies on the time of year and amount of sun. It's also to pale me or others out. The powders are used to set liquid bases or water and grease makeups. And at the bottom of the picture are for highlights and shadows for basic corrective (I will be doing a blog on this soon).
As far as finding these, you can get them just about anywhere. The cheaper ones will be at grocery stores and a cheep way to get a highlight and shadow would be to merely get a brown and off white eyeshadow. The color will depend on your sin tone. Normally you go two to three shades lighter or darker than what you skin tone is. Or you can get more expensive bases as well as high light and shadow at specialty makeup stores such as Kryolan (I will provide a link to their website at the end of the blog).
Here we have liners and glosses along with a few other things. Left hand side there's some teeth stains, these great for zombie or vampire looks as it means you can give the teeth a bloody or decayed look. I've only really seen them at Kryolon, though around Halloween you can find a black tooth wax.
My lip glosses and eyeliners come in many colors. I have sparkles, pink, white, gold and I use them for a ton of different things. White eyeliner is especially useful for giving a highlight under the eye to make them pop.
Mascaras are also various in colors. Black, clear and silver, though there are many others you can find as well. Any of these can be found at most stores for relatively cheap prices if you look around some.
The glues stick and cork are more specialty items. The glue stick is used, with a bit of base and cover up, to take out eyebrows if you should want to move them higher or make them thinner (drag queens use this when they're in drag). The cork is used for creating dirt smears. Burn one end and then smudge it on your face. And the price is very cheep for both of these!
Hair and sparkles. Bobby-pins are useful to have to keep your hair out of your face (or a friend's hair) when your working as well as to create simple or complex hair styles. And sparkles are...well...sparkles. Great for princesses or whatever...
Here's the stuff used for creating 3-D effects, such as wounds, new noses, whatever you might want. The main key to this is liquid latex, easy to find during Halloween, otherwise you can use skool glue (this is also cheaper for the most part).
With latex you attach and mold tissue and cotton balls to create a three-dementional look. Molding wax is used for a better and smoother look, however it doesn't usually last as long. You should cover the wax with latex as well.
Spirit gum attached things such as fake hair for mustaches or beards but be sure to have remover as well, other wise you'll definitely feel it later. You can get it cheap around halloween, other wise I've only seen it at Kryolan. However, the stuff at Kryolan is definitely of better quality.
Aqua colors are wonderful for basing (especially red for anything you want to be bloody). White and off white work for highlighting, black and brown for shadows. The sponges give texturing. However, Aqua color isn't cheep and can be found through Krylon. There may be a cheaper alternative out there but I don't know about it.
Eyeshadows...have plenty you can use them for everything! From coloring wounds to making glamor eye effects. Their use is truly limitless!
There are two types of fake blood here, liquid (the one in the tube is from a halloween store and the ones in the bottles are from Kryolan. I prefer the Kryolan one due to thickness and texture. The other one is really thin and watery.) The fresh scratch can be used to get a road rash effect as it is thicker than liquid blood and doesn't run. These ones are from Kryolan, however you can get some at halloween stores for less.
The lotion is for prepping skin to keep the makeup from getting in your pours. And you don't need to get a special brush cleaner as dish soap works quite well.
The cleaners I have here are Hydro (from Kryolan) which is theatre grade makeup remover, and some special stuff for getting makeup off from around eyes, which is always helpful. You should also have face or baby wipes for after use of the other stuff, I'm jut out at the moment.
A variety of brushes is truly helpful. Blush brushes are good for large spread of powder makeup. Smaller brusher or flat brush work better for details and oil work. While I have mac brushes (on the right hand side) I also have cheap pain brushes for oil makeups and such (on the left hand side).
Oil based makeups in convenient wheels. I have three (shown above) all from Kryolan. I use them quite often when I'm making things. However, there are different things you can get that will work just as well.
There are a few things I didn't list or put picture of up such as fake eyelashes (I have tons of many colors an shapes). These are fun for added effects but not at all necessary. I also have blushes, which are kind of pictured but not talked about. Having on blush that's a good color for you is plenty for most things.
Check out stage and film makeup at: http://www.kryolan.com/index.php