[Q] How would I increase net worth?

I recently picked up TF2 again and am looking to make some money off of it for college. Considering I have read that idle farming is not an efficient way to make money, how does someone increase their net worth relatively quickly so that some money can be made?

Here is my backpack: http://backpack.tf/id/znaught

I was thinking about possibly using Sandboxie to idle, but I am not sure how that approach would work either. I am just hoping to make some money for college if possible.

Thanks