Sort:  

Oh, it is just a skill that anyone can learn. I mean, all this stuff is sitting in the bins and I was certainly not the first to go through it all.

So it's mainly a matter of learning what people are buying and what you can reasonably make some money off of. You buy what you can and then see how it goes. What's your carrier of choice? Do you use one type of container (eg envelope, box, flat-rate) or do you vary it?