If you're about to rent any sort of equipment, from party dishes to construction cranes, you know you have to check the goods over carefully to ensure you note any chips, dents, or other damage, and you know you have to avoid damaging the items yourself. However, there are also a few steps you have to take before returning the items, too. It's often not good enough to just drop the equipment off as is. Before returning any rental items, go over these three tasks to increase the chances of you getting your full deposit back and not being charged extra.
Fuel
Rental cars aren't the only items that have to be filled up with fuel lest you get hit with fuel charges. Any lawn equipment, construction vehicles, and tools generally have to be filled up as well. Some companies offer various deals, like pre-purchasing gas or tacking on some other surcharges, but if you don't have one of those, you'll have to fill the tank to at least the point it was at when you got the equipment.
Soil, Dirt, and Stains
Check over the equipment for dirt. A little dust is usually fine, and tires are likely to be dirty no matter what you do. But garden tools shouldn't be covered in soil, for example. Brush off loose dirt; do not wash off mud unless the company says it's OK to use water on the item (use a company-sanctioned cleanser instead). Rinse and air dry any dishes or utensils that you rented for a party.
There is an exception to the cleaning rule: Linens. If you've rented items for a party including furniture, table cloths, and so on, and the linens become dirty, don't wash them unless you have specific care instructions for the material. You may end up shrinking the linens to the point where they are unusable. Many party rental companies offer dirty-linen bags where you can place the items.
Pictures
The final step is to take pictures if possible. If you've rented lots of dishes for a party, this might be difficult, but if you rented tools, take a picture of all sides of the tool in good lighting. If you can, print out the pictures so that you don't have to worry about losing them if something happens to the data files (even better, find a non-digital camera and use that).
If you have other questions about what to do before returning commercial rental equipment, ask to see the policy for each rental company you're considering renting from. Sometimes the companies have very good deals that leave a lot of the cleaning to their staff, too.