Ok, it seems a little odd to start a post on wagonloads with a couple of vans but they do give away subtle signs that they are actually earning money and not just trundling around.  Chalk markings and labels are the give-away here.  The chalk markings are done with a sharp chinagraph pencil which allows you to smudge them and rub them out. Much as could be found on the real thing. The labels are from Hollar Models and can be distressed with a scalpel or fibreglass brush before applying. The easiest loads are the loose ones such as coal, ore, ballast etc. This is real coal glued to a foam former (the dark foam in RTR loco packing is ideal). Remember to weather the inside of the wagon first though. One loose load I struggled a little with was coke. In the end I used larger lumps of coal but when set sprayed it with gunmetal to give the dull look coke has. Sheeted loads tend to come in 2 forms. Above the load is sheeted as a stand alone item.  This was a cheap load i found on ebay. The second form is that the load is added to the wagon and then the load and the wagon itself is sheeted over. These are more cheap loads from Ebay which were quite crude. The sheeting is black latex cut from a surgical glove. Sometimes the load is just open to the elements. This is a drawbar converter from Langley Models.Finally, sometimes the load is a wagon itself. An RT Models molten slag wagon loaded onto a Lowmac and ARM-E