The top leveling powder measures usually have a funnel on top to get the best volume measure I fill it a bit past full and slide top over the measure. I have a empty powder can which the excess goes into when at the range so as not to waste any. There are several brands some hinge some slide.
http://www.midsouthshooterssupply.com/item.asp?sku=000307222
You should find a sample of the type here. Lee