Oh, I must have missed this thread when it was first posted. One of my favourite topics! When olive oil is $10/bottle and butter is $5.99/lb, why waste good cooking fat?

My tips:

• If you only have a small amount, it's probably not worth rendering on the stove. Small amounts, I'll just keep it in a small container in the fridge and it gets used up pretty quickly. I just keep in mind that it might be "brothy" and is probably going to spatter in the pan.
• The purpose of rendering is to cook the water out. This helps preserve it. My technique is like above, but basically as if I'm making clarified butter: cook it on the stove low and slow until it stops bubbling. Most of the time I'm rendering, it's fat I peeled off a bowl of chilled broth.
• Highly recommended: get yourself a stainless steel coffee filter for your cooked-and-cooled liquid fat. It'll take out the blackened bits, meaty bits, and spice chunks left over. It makes a nicer cooking fat less likely to smoke or burn.
• If you made bacon, the grease is already virtually water-free because it was being pan-fried or baked. By the time the bacon is done, there's little or no water left.
• Don't be afraid of fats that are from something that was flavoured. Some of the best chicken fat and lard I ever had was from rotisserie chicken, pulled pork, sausage grease, etc. Just jot down what it was so you don't surprise yourself later.