Pour directly from the bottle (for prepared marinades, dressings, etc.) Alternatively, make a funnel from an empty plastic liter bottle. Test to see that the mouth fits the bellows opening. Carefully cut a funnel with a sharp knife or scissors. Don't cut yourself. Save the funnel for repeated usage. Another easy tip for filling a bellows is support a plastic sandwich bag over a small jar or glass. Fill the bag. Remove the bag while squeezing the opening closed. Make a small diagonal cut in one corner of the bag and squeeze the contents into the bellows.