BKE: I don't know if anyone has already suggested this, but I have always found it handy to pre-measure a few loads and carry them in small containers in the field. That way, you can forget about a flask and a measure when you're hunting. I have used pill bottles, film canisters and various other small bottles. I have recently switched to "speed loaders". They can be purchased at Walmart and other stores, or ordered from Cabela's, etc. They will hold your charge as well as your projectile for each load. Some also will hold the cap or primer, depending on what type you get. Some have a very short starter built in, and then you push the bullet down with your ram rod.
They come in different colors for different calibers (so the bullet fits snugly and doesn't rattle around). Mine also have a pocket clip so I keep one clipped right in my shirt pocket with extras in my fanny pack.

Good Luck