There are some basic cellermanship tasks that anyone should serving draught cask ale should be aware of.
In order to prevent additional loss of carbonation as well as excessive oxygen exposure, in-service casks are often sealed with a hard spile overnight. However, if the hard spile is left in during service, a vacuum can form as beer is drawn in from the cask, making it exceedingly difficult to pull a pint. Hard spiles should be removed from all in-service casks at the beginning of service, and replaced at the end of the night.
Properly handled cask beer should always pour bright, or brilliantly clear. Various things can cause cloudy cask beer, such as not stillaging the cask for long enough prior to service or physically disturbing the cask while in service. If a cask begins to pour cloudy and is not nearly empty, it should be removed from service until the issue can be assessed and dealt with.