I was making up my weekly meal list a couple of weeks ago and was contemplating adding a dish that required chile oil. I didn't have any such oil in the cupboard and didn't want to spend money buying some, so I made up a little batch, and it took hardly any time at all.
I put some canola oil in a small pot over low heat (you DON'T want the oil to boil!), and added some dried chiles. A couple of spoonfuls. I let the oil and chile infuse for 20 minutes or so, then turned off the heat and let it cool completely.
I strained the oil thru a coffee filter to get out all the chiles and poured it into a small bottle.
Pretty, cheap, and delicious to boot.